GITNUXSOFTWARE REVIEW
Construction InfrastructureTop 10 Best Duct Calculator Software of 2026
Compare duct calculator software options for HVAC duct sizing and fitting calculations, including tools like Autodesk Revit and Carmel Software.
How we ranked these tools
Vendors set the topic, but our editors set the inclusion criteria and the evaluation framework before research starts.
Agents extract product evidence with provenance, then collect written reviews and transcribe video reviews and podcasts.
Framework: Features 40% · Ease 30% · Value 30%
Gitnux may earn a commission through links on this page. This does not influence our reviews. Editorial policy
Autodesk Revit is the best overall pick for teams who need duct sizing to stay synced to their modeled MEP systems because the Revit API lets you automate updates and publish schedule data, while ASHRAE Duct Fitting Database is ideal when you just need defensible fitting loss coefficients for repeatable calculations.
Editor’s top 3 picks
Three quick recommendations before you dive into the full comparison below — each one leads on a different dimension.
Autodesk Revit
Revit API supports custom add-ins that read and update MEP system sizing parameters and publish schedule data.
Best for: Fits when teams need model-synchronized duct sizing with API-driven configuration and reporting.
ASHRAE Duct Fitting Database
Editor pickDuct-fitting library centered on fitting-specific loss coefficient values, optimized for calculation inputs rather than CAD automation.
Best for: Fits when teams need a defensible duct fitting loss coefficient reference for existing sizing methods and internal tooling.
Carmel Software Duct Calculator
Editor pickThe friction-loss and pressure-drop calculation workflow stays in a single input-output cycle, optimized for rapid sizing revisions.
Best for: Fits when HVAC designers need repeatable duct sizing and pressure-drop checks outside a full BIM workflow.
Comparison Table
Autodesk Revit
enterpriseBIM platform with MEP ductwork modeling tools including automated duct sizing based on airflow and friction loss.
Revit API supports custom add-ins that read and update MEP system sizing parameters and publish schedule data.
Revit MEP can manage duct runs as elements tied to system types, which enables consistent sizing inputs across design drawings and schedules. Duct fitting library content and mechanical system parameters let teams generate downstream reporting for coordination. Automation is available through the Revit API and add-in extensibility points, which supports repeatable configuration for pressure loss rules and schedule outputs.
A key tradeoff is that Revit’s duct sizing behavior depends on how the MEP system settings and calculated parameters are configured for the project, so models created with inconsistent standards can produce inconsistent results. Revit fits best when duct sizing and layout must remain synchronized with coordination outputs like ducts, fittings, and tags for commissioning-style airflow reports.
- +Parametric duct elements keep sizes consistent with modeled geometry
- +Revit API supports automation of sizing workflows and schedule extraction
- +MEP interoperability workflows reduce rework between design and documentation
- +Fitting library content ties fittings to duct system behavior
- –Sizing output quality depends on MEP system settings discipline
- –Standalone duct sizing speed can lag spreadsheet calculators for bulk sizing
MEP design automation teams
Auto-generate duct system schedules
Repeatable reporting across projects
Large design firms
Enforce duct standards per system type
Lower rework during revisions
Show 1 more scenario
Coordinated BIM project teams
Synchronize sizing with routed geometry
Fewer mismatches in drawings
Duct element parameters update with routing changes to keep design intent and documentation consistent.
Best for: Fits when teams need model-synchronized duct sizing with API-driven configuration and reporting.
ASHRAE Duct Fitting Database
vertical specialistAuthoritative database and calculator for pressure loss coefficients across standardized duct fittings.
Duct-fitting library centered on fitting-specific loss coefficient values, optimized for calculation inputs rather than CAD automation.
ASHRAE Duct Fitting Database provides a reference duct fitting library used to determine fitting loss coefficients for duct system calculations. It is distinct because the content is curated as fitting-specific lookup data rather than being a full duct sizing workflow tied to one CAD or simulation stack.
The database supports friction loss planning by mapping common fitting types to coefficient values used in standard duct sizing methods. In practice, it fits into workflows where duct design teams already compute pressure loss and need defensible fitting data.
- +Curated fitting loss coefficient library for repeatable pressure-loss inputs
- +Clear fitting-type mapping that reduces manual coefficient lookup errors
- +Reference-first design that suits multiple sizing methods and internal calculators
- +Common duct elements included for typical HVAC layout calculations
- –Limited support for end-to-end duct sizing and output reporting workflows
- –No built-in import path for Revit models in a typical design-to-calc flow
- –Lookup-based interaction can slow batch coefficient extraction for many parts
- –May require tailoring to align with local pressure class and construction assumptions
Duct design engineers
Compute fitting loss coefficients
Defensible fitting loss calculations
HVAC pressure-loss analysts
Standardize coefficients across projects
Consistent loss coefficient assumptions
Show 1 more scenario
MEP design teams
Validate duct sizing inputs
Reduced rework for assumptions
Reference curated fitting data to support checks against duct sizing methods that require loss coefficients.
Best for: Fits when teams need a defensible duct fitting loss coefficient reference for existing sizing methods and internal tooling.
Carmel Software Duct Calculator
vertical specialistHVAC duct sizing application available for desktop and mobile platforms that calculates duct dimensions using equal friction or static regain methods.
The friction-loss and pressure-drop calculation workflow stays in a single input-output cycle, optimized for rapid sizing revisions.
Carmel Software Duct Calculator fits teams that need consistent duct dimension outputs for load cases and system studies, including static pressure allocation. The calculator emphasizes friction-loss and equivalent-length style loss handling so designers can adjust duct sizes and flow assumptions quickly. Results are computed from the chosen duct geometry and airflow inputs, with options to include loss contributors so the pressure budget reflects fittings and run length.
A key tradeoff is limited model interoperability since the workflow is calculation-first rather than model-first. Carmel Software Duct Calculator works best when the goal is a repeatable sizing spreadsheet for review and coordination, not when the deliverable is a duct layout file for installation. It is also better used for focused sizing packages than for end-to-end design documentation that spans model edits across systems.
- +Calculation-first workflow prioritizes friction-loss budgeting over model management
- +Parameter-driven inputs make it practical for multiple design iterations
- +Fitting and run loss inclusion supports more realistic pressure estimates
- +Results stay focused on sizing outputs for quick review cycles
- –Limited BIM and CAD handoff support compared with Revit-based workflows
- –Governance controls are not designed for multi-user controlled projects
- –Advanced automation and API integration surface is not emphasized
- –Output formats for construction drawings are not the primary focus
HVAC design engineers
Iterate duct sizes against pressure budget
Faster pressure-budget convergence
Consulting HVAC firms
Standardize duct sizing review packages
More consistent review outputs
Show 2 more scenarios
Commissioning and balancing teams
Sanity-check terminal airflow assumptions
Fewer late coordination issues
Compare intended duct sizing pressure losses with airflow targets before site measurements.
Controls and system integration
Support static pressure planning
Better static planning inputs
Translate duct pressure-loss results into planning inputs for air-side control strategies.
Best for: Fits when HVAC designers need repeatable duct sizing and pressure-drop checks outside a full BIM workflow.
Trane TRACE 3D Plus
enterpriseComprehensive HVAC load analysis and system design software that includes duct sizing and air distribution calculation modules.
Integrated duct sizing that tracks pressure loss calculations directly from the HVAC design model context.
TRACE 3D Plus is built around HVAC design inputs and then applies duct fitting and pressure loss calculations to reach duct selections that match the rest of the system model. It supports rectangular duct sizing outcomes and includes constraints needed to control airflow behavior during sizing runs. In typical workflows, engineers use it to generate a duct path that aligns with system performance targets and commissioning expectations for airflow distribution.
- +Tight coupling between duct sizing results and HVAC system model inputs
- +Friction and fitting loss calculations update through iterative design changes
- +Geometry-aware rectangular duct outputs support distribution layout work
- +Outputs are aligned with equipment-centric design documentation workflows
- –Duct-only use requires more input mapping when equipment assumptions differ
- –Layout-level exports can require manual cleanup for downstream drafting
HVAC design engineers
Iterative duct sizing during system redesign
Fewer rework cycles on duct picks
Engineering design coordinators
Coordinated duct layout documentation
More consistent design package content
Show 2 more scenarios
Commissioning and balancing teams
Align duct sizing with airflow targets
Cleaner airflow distribution baselines
Uses duct loss-aware sizing outputs to support downstream airflow budgeting for balancing plans.
Consulting firms
Standardized duct configuration workflows
More consistent outcomes across projects
Applies repeatable inputs to produce duct sizing results that match office standards across projects.
Best for: Fits when HVAC design teams need duct sizing that stays consistent with system selections.
Cool Calc
SMBWeb-based ACCA-approved HVAC design software covering Manual J load calculations, Manual S equipment selection, and Manual D duct design.
Fitting-loss coefficient driven pressure drop budgeting that accounts for components beyond straight duct runs.
Cool Calc is a duct calculator tool built for fast duct sizing with workflow-style inputs for air flow, duct geometry, and pressure loss. It focuses on engineering calculations like equivalent diameter conversion, fitting loss coefficient handling, and pressure drop budgeting across straight runs and transitions.
- +Quick duct sizing loops with geometry and flow entered in a single workspace
- +Includes fitting-loss coefficient based pressure loss across duct components
- +Converts rectangular duct geometry using circular equivalent diameter logic
- +Produces consistent outputs that support iterative design comparisons
- –Limited automation surface for bulk recalculation and scheduled batch runs
- –Fewer governance controls for multi-user engineering workflows than BIM-centric tools
- –Interoperability depends on output format support for BIM and drafting pipelines
- –No native CFD-style modeling workflow for complex flow phenomena
Residential HVAC designers
Compare airflow across duct iterations
Faster early distribution decisions
Early-stage HVAC teams
Scope ducts during preliminary design
Practical schematic tradeoffs
Show 2 more scenarios
HVAC sizing teams
Consolidate room results into zones
Aligned zone and building totals
Combine individual room calculations into consistent zone and building totals for multi-area HVAC planning.
Residential contractors
Estimate heating and cooling by room
Room-level sizing targets
Calculate room-level requirements from building and operating-condition inputs to support sizing decisions.
Best for: Fits when design teams need rapid duct sizing iterations and pressure loss budgets without running full BIM-based mechanical modeling.
Wrightsoft Right Suite
SMBResidential and commercial HVAC design suite including duct sizing modules compliant with ACCA Manual D.
Integrated sizing-to-layout workflow that keeps duct dimensions consistent between calculation results and drawing deliverables.
Wrightsoft Right Suite centers on duct sizing workflows tied to HVAC design specifications and project documentation, rather than generic geometry tools. It supports duct dimensioning based on selectable design approaches and includes detailed fitting and loss handling needed for ventilation system calculations. The suite’s distinguishing angle is tight linkage between sizing outputs and drafting deliverables, which reduces rework when drawings and schedules need to match the calculated duct runs.
- +Workflow links duct sizing outputs to drafting deliverables for fewer mismatches
- +Fitting-loss and pressure-budget style calculations support more than diameter-only sizing
- +Supports rectangular ductwork optimization paths for plan-driven layouts
- +Library-driven repeatability helps teams standardize duct assumptions across projects
- –Best results require careful upfront configuration of design criteria and defaults
- –Automation depth for downstream formats can be limited outside supported export targets
- –Complex multi-branch balancing reports may take manual checking for large systems
- –Version-to-version workflow changes can force template updates for established teams
Duct designers and contractors
Coordinate routes and sizing across rooms
Coordinated duct layouts
Sheet-metal fabrication teams
Prepare drawings for installation handoff
Less manual redrawing
Show 2 more scenarios
Residential HVAC designers
Carry floor plan geometry through design
Coordinated system design
Model new residential floor plans and use room geometry to support heating, cooling, equipment, and duct sizing.
HVAC survey teams
Produce repeatable heat loss results
Reportable room survey results
Record envelope and internal-load inputs to generate consistent room-level heat loss and heat gain outputs.
Best for: Fits when teams need duct sizing plus matching drafting outputs, and can standardize design assumptions.
Ductsize
vertical specialistDedicated duct sizing software calculating optimal duct dimensions based on static regain, equal friction, or constant velocity methods.
Batch-style runs that keep duct sizing inputs consistent across multiple segments and deliver consolidated pressure and size outputs.
Ductsize from elitesoft.com focuses on duct sizing workflows that support common HVAC sizing methods and outputs for design checks. It provides a calculator-centric experience with input forms for duct dimensions and airside targets, then returns calculated pressure and sizing results needed for selection.
- +Calculator-first workflow that quickly produces duct sizes and pressure results
- +Supports both rectangular and circular duct sizing with consistent output format
- +Provides friction-loss style pressure budgeting outputs for design iterations
- +Exports results in formats commonly used for handoff into drafting tools
- –Fitting loss coefficient coverage can be limited without a complete library
- –Workflow depth for long duct routes is less automation heavy than model-based tools
- –Parameter governance across multi-discipline projects needs manual checking
- –Integration to Revit workflows is not centered on native model updates
HVAC engineers
Select ducts from pressure and airflow
Repeatable duct selections
HVAC planners and coordinators
Build duct schedules from results
Procurement-ready schedule data
Show 2 more scenarios
Retrofit designers
Recalculate sizing after route changes
Updated fan-duty implications
Update duct branches and equipment airflow impacts when routes or capture points change.
CAD coordination teams
Feed consistent data into drafting
More consistent drawing inputs
Use duct calculations as inputs for plan or riser documentation to support CAD drafting production.
Best for: Fits when teams need fast, repeatable duct sizing and pressure results without a full 3D authoring pipeline.
Carrier HAP
enterpriseHourly Analysis Program for commercial building load calculations that includes air system and duct design sizing capabilities.
Air system simulation context that keeps duct sizing tied to zone loads and airflow targets in one consistent run.
Carrier HAP calculates heating and cooling loads with duct and airflow sizing inputs tied to building zone definitions. The workflow uses a structured psychrometric and air system model to carry results from room loads through air distribution assumptions.
- +Applies duct and airflow decisions inside a full load and system model
- +Maintains consistent assumptions from zone loads through distribution sizing
- +Supports extensive HVAC configuration options for air-side planning
- +Produces repeatable results when team assumptions stay aligned
- –Duct sizing detail depends on how air distribution inputs are defined
- –Geometry-first duct layout exports like DXF are not its core workflow
Commercial HVAC engineering teams
Run code-aligned load workflows
More consistent design assumptions
MEP design documentation teams
Generate report-ready load summaries
Review-ready load documentation
Show 2 more scenarios
Building designers
Compare envelope and infiltration scenarios
Comparable load results
Test how envelope assemblies and infiltration assumptions change design loads that drive duct and airflow sizing.
Building energy analysts
Assess hourly energy impacts
Hourly load and energy breakdowns
Evaluate how equipment, controls, schedules, and plant assumptions affect hourly energy use and load breakdowns.
Best for: Fits when design teams need duct-related airflow sizing as part of system load modeling across many zones.
Design Master HVAC
vertical specialistAutoCAD-integrated HVAC design software with built-in duct sizing and pressure loss calculation capabilities.
Route and segment driven duct sizing that keeps friction and fitting loss calculations tied to the entered layout segments.
Design Master HVAC is a duct calculator focused on producing duct sizes from entered airflows and layout details, with guidance around ductwork construction assumptions.
- +Calculator workflow reduces spreadsheet math during iterative duct sizing
- +Library-based fitting loss inputs help keep loss assumptions consistent
- +Layout-driven sizing keeps results tied to route and segment data
- +Export and reuse support document handoff without rebuilding calculations
- –Limited pathway for full BIM coordination compared with Revit MEP
- –Less automation for batch updates across many zones and branches
- –Fitting and construction assumptions can require careful upfront selection
- –Governance controls like RBAC and audit logs are not emphasized
Mechanical engineers
Layout and size supply and return ducts
2D duct layout with sizing
HVAC design coordinators
Update drawings after parameter changes
More consistent revision packages
Show 2 more scenarios
HVAC estimators
Generate takeoff-style scope information
Estimate-ready duct scope
Produce material and scope information from planned duct routes and system layouts.
Mechanical engineering firms
Document pressure-loss calculations
Traceable calculation reports
Apply duct, fitting, and transition assumptions to produce traceable friction and pressure-loss documentation.
Best for: Fits when duct sizing accuracy needs repeatability across multiple routes without heavy BIM workflows.
Greenheck Ductulator
vertical specialistOnline duct sizing calculator for airflow, velocity, and friction-loss estimates.
Friction and fitting losses are calculated together from selectable sizing assumptions within a worksheet workflow.
Greenheck Ductulator is a duct sizing calculator focused on quick, repeatable duct sizing using selectable method options and standard input fields for airflow, duct geometry, and pressure loss. Core calculations include friction loss and fitting loss contributions so sized ducts reflect both straight-run pressure effects and common component impacts.
- +Method choices support different loss calculation assumptions during sizing
- +Worksheet-style outputs make it easy to iterate duct size inputs
- +Includes fitting loss allowance rather than straight-run loss only
- +Straightforward inputs for airflow, duct geometry, and pressure constraints
- –Limited automation and API surface for workflow integration
- –CAD and model exports for Revit workflows are not a native focus
- –Fewer governance controls than enterprise design review toolchains
- –Does not cover advanced simulation workflows like CFD airflow modeling
HVAC design drafters
Size ducts using worksheet inputs
Quick duct sizing worksheets
Ventilation designers
Account for fitting losses
More complete pressure-loss modeling
Show 2 more scenarios
Design iteration teams
Test diameter and loss assumption changes
Faster iteration cycles
Adjust diameter, size, and selected loss assumptions to iterate on results using worksheet-style outputs.
Small design teams
Produce duct candidates without CAD linkage
Candidate sizes in minutes
Generate candidate sizes efficiently from design inputs when deep CAD-linked workflows are not required.
Best for: Fits when teams need fast duct size calculations with fitting allowances without model integration demands.
Conclusion
After evaluating 10 duct calculator software, Autodesk Revit stands out as our overall top pick — it scored highest across our combined criteria of features, ease of use, and value, which is why it sits at #1 in the rankings above.
Use the comparison table and detailed reviews above to validate the fit against your own requirements before committing to a tool.
Frequently Asked Questions About Duct Calculator Software
How does Trane TRACE 3D Plus keep duct sizing aligned with HVAC system selections?
When does a worksheet-focused tool like Carmel Software Duct Calculator outperform model-driven sizing in Revit?
What breaks if duct calculations are done in a calculator that does not follow Revit MEP parameter rules?
How does the ASHRAE Duct Fitting Database support defensible fitting loss inputs?
Which integration approach matters most when duct sizing must publish schedules and configuration data?
How do batch workflows change duct sizing repeatability in Ductsize?
When does Wrightsoft Right Suite provide a tighter handoff than a sizing worksheet tool?
What tradeoff appears when Cool Calc is used for pressure budgeting without CAD-linked modeling?
Where does Carrier HAP fit when duct sizing depends on zones and air distribution assumptions?
Tools reviewed
Primary sources checked during evaluation.
Referenced in the comparison table and product reviews above.
How to Choose the Right Duct Calculator Software
We look for duct calculator software options that separate themselves by calculation coverage and how reproducibly they produce results for your exact inputs. The biggest differences show up in duct fitting loss handling and how well the tool matches the same geometry and data you maintain day to day.
Duct geometry and method coverage
Why it matters
Duct geometry and method coverage matters because two tools may differ on what counts as an acceptable duct shape, and that changes friction and equivalent length style outputs. If your projects include mixed rectangular and round runs, gaps here show up quickly.
How to check
Ask for a sample calculation using one round duct segment and one rectangular segment, then compare the assumptions shown in the output. Confirm the tool lets you enter the geometry you use in practice (outside/inside dimensions and wall thickness if needed).
Fitting loss model transparency
Why it matters
Fitting loss model transparency is where duct calculator software often diverges, because losses can be handled via coefficients, equivalent lengths, or a library lookup. When the model isn’t visible, you can’t reconcile results with your team’s expectations.
How to check
Run a scenario with at least three fittings (for example an elbow, a tee, and a transition). In the results, look for an explicit per-fitting breakdown and a way to view or edit the fitting assumptions.
Editable duct and fitting libraries
Why it matters
Editable duct and fitting libraries matter because organizations often have their own coefficient tables and custom fitting entries. If you can’t adjust or version the libraries, repeatability drops across projects.
How to check
During a demo, request adding a custom fitting and overriding an existing coefficient. Verify the tool can reuse your updated values in a new calculation without rebuilding settings each time.
Outputs tied to inputs
Why it matters
Outputs tied to inputs matters because duct calculator software should show which segment, which airflow, and which loss components drove the final pressure or head result. Without clear traceability, troubleshooting becomes guesswork.
How to check
Change one variable (airflow rate or duct length) and confirm the output updates with a segment-by-segment recalculation. Export or review the report and check that each line item maps to an entered run element.
Import/export and automation surface
Why it matters
Import/export and automation surface affects throughput when you reuse the same ductwork data across jobs. If the tool only supports manual re-entry, teams typically spend time recreating the input model rather than validating results.
How to check
Ask what file formats or data exchange options exist for importing duct layouts and exporting results. If available, request an API or batch mode demo and verify it can run the same calculation headlessly from a prepared input set.
Red flags
- Results change after edits, but the report won’t show what inputs drove the new numbers
- Fitting losses are included, yet the breakdown or assumptions per fitting can’t be viewed or edited
- The tool limits your duct shapes or geometry inputs in a way that forces unrealistic workarounds
Fit by situation
- If your duct runs mix round and rectangular segments, prioritize duct geometry and method coverage.
- If your team reconciles pressure results fitting-by-fitting, prioritize fitting loss model transparency.
- If you need to reuse the same duct data across projects or automate runs, prioritize import/export and automation surface.
Funding and competing interests
This study was co-funded by several of the vendors assessed in it. No single vendor funded it. Funders could propose the market studied.
They had no role in selecting vendors, setting or weighting criteria, analysing data or drawing conclusions, and they received the same factual-accuracy check as every other vendor assessed.
Market definition, inclusion rules and criteria weights were fixed by an editor before research began and did not change afterwards. Editorial process →
- Review · 2026 · Construction InfrastructureDuct Software
- Review · 2026 · Construction InfrastructureHvac Calculator Software
- Review · 2026 · Real Estate PropertyResidential Duct Design Software
- Review · 2026 · Personal Care ServicesDuct Cleaning Software
- Review · 2026 · Construction InfrastructureDuct Sizer Software
Keep exploring
Comparing two specific tools?
Software Alternatives
See head-to-head software comparisons with feature breakdowns, pricing, and our recommendation for each use case.
Explore software alternatives→In this category
Construction Infrastructure alternatives
See side-by-side comparisons of construction infrastructure tools and pick the right one for your stack.
Compare construction infrastructure tools→