Ductulator: Duct Calculator

Foster Apps LLC

In-app purchases

About this app

Ductulator is a duct size calculator for HVAC work. Enter the airflow in CFM and get the round or rectangular duct size you need, with the friction rate and air velocity, right from the job site.

Built for HVAC contractors, installers and DIY homeowners who want duct sizing without a paper ductulator or a spreadsheet.

— DUCT SIZING (FREE) —
• Round duct sizing from CFM and target velocity
• Rectangular duct sizing from CFM and target velocity
• Friction rate shown with every result
• Results update as you type, so you can try sizes on the spot
• Imperial (CFM, inches) or metric (m³/h, mm, Pa/m): switch any time in Settings

— REFERENCE CHART (FREE) —
• Typical CFM ranges by room: bathroom exhaust, kitchen hood, bedroom, living room, laundry room, whole-house supply
• Target velocities by duct type, from the main trunk to the branch runs

— PRO —
• Reverse mode: already have a duct on hand? See how much airflow it can carry
• Trunk and branch calculator: size a trunk and every branch run at once, with a warning when the branches don't add up
• Duct materials: galvanized steel, flex duct, PVC and fiberboard, each with its own friction
• Save sizings by job and share a clean PDF with your crew or customer

Pro is available as a weekly subscription with a free trial or as a yearly subscription. You can cancel anytime in Google Play under Payments & subscriptions.

No account and no ads. Just the duct size, friction rate and velocity you need before you cut metal.

Privacy Policy: https://fosterapps.com/duct/privacy/
Terms of Use: https://fosterapps.com/duct/terms/

What’s new

First release: duct size calculator in imperial (CFM, inches) or metric (m³/h, mm).