Ductulator: HVAC Calculator
Airflow, CFM & Duct Sizing
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
Size a duct from airflow in seconds — round, rectangular, or a whole trunk-and-branch run, right from the job site.
Stop guessing duct sizes.
Ductulator turns your airflow into the exact round or rectangular duct size you need — plus the friction rate, right from the job site.
Built for HVAC contractors and DIY installs alike:
• Round and rectangular sizing from CFM and target velocity, fully free
• Reverse mode — already have a duct size on hand? See what airflow it can carry (Pro)
• Branch calculator — size a trunk and every branch run at once, with a warning if they don't add up (Pro)
• Every duct material — Galvanized, Flex Duct, PVC, Fiberboard (Pro)
• Save sizings by job and share a polished PDF with your crew (Pro)
No account, no ads, no guesswork — just the numbers you need before you cut metal.
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Privacy Policy: https://fosterapps.com/duct/privacy/
Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Minor fixes and improvements.
The developer, Foster Apps LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Foster Apps LLC
- Size
- 30 MB
- Category
- Utilities
- Compatibility
Requires iOS 15.1 or later.
- iPhone
Requires iOS 15.1 or later. - iPad
Requires iPadOS 15.1 or later. - iPod touch
Requires iOS 15.1 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
English and 7 more
- English, French, German, Japanese, Korean, Portuguese, Simplified Chinese, Spanish
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Pro Yearly $29.99
- Pro Weekly $4.99
- Copyright
- © 2026 Foster Apps LLC