Duct Calc: HVAC Duct Sizer

1.0.1

witty apps

0.00

0 reviews

10+
Downloads

Free

HVAC duct sizing calculator — round, rectangular & flex. CFM, friction, offline

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About Duct Calc: HVAC Duct Sizer

Duct Calc: HVAC Duct Sizer is a tools app developed by witty apps.

Download Statistics

Duct Calc: HVAC Duct Sizer has been downloaded 37 times. In the last 30 days, the app was downloaded 37 times.

User Ratings

The app has no ratings yet.

App Information

Duct Calc: HVAC Duct Sizer is FREE to download. The APK download size is 20.85 MB. The latest version available is 1.0.1. The last update was on August 1, 2026.

Technical Requirements

The app has a content rating of Everyone. The app has been available on Google Play 4 weeks ago.

Description

Size ductwork in seconds — round, rectangular, and yes, flex.

Duct Calc is an offline HVAC duct calculator built for techs and designers who need answers on the job, not another subscription.

FREE, FULLY WORKING
• Duct sizing (equal friction, round) — enter CFM and friction rate (in. w.c./100 ft), get the exact diameter, the stock size to grab, and the velocity in FPM
• Unit converter — airflow, velocity, and duct area. CFM · L/s · m³/h at one tap

PRO (ONE-TIME PURCHASE)
• Flex duct sizing — friction based on published research data (fully stretched to 30% compressed). Compressed flex loses far more pressure than the charts admit; Duct Calc corrects for it
• Rectangular conversion — equivalent diameter to W×H (1-inch increments), with aspect-ratio warning
• Airflow back-calc — know the duct, get the CFM: from round diameter or rectangular W×H, by velocity or friction rate
• Register / diffuser selection — neck size, free area, and throw estimate from CFM and neck velocity
• Static pressure — straight-run loss plus fittings (elbows, tees, transitions), totaled in in. w.c.

BUILT FOR THE FIELD
• 100% offline — works in the attic, the crawlspace, the mechanical room
• Big touch targets, screen stays awake, no account, no sign-in
• Your inputs never leave the device

ONE-TIME PURCHASE
The free version is fully functional — round sizing and conversion are never crippled. One purchase unlocks everything else, forever.

No subscription. No ads. No features taken away later.

Calculations follow standard practice (Darcy–Weisbach / Colebrook friction, ASHRAE equivalent-diameter equation, published flex-duct compression data). Reference only — verify final designs against applicable codes and manufacturer data.

Recent changes:
Stability and reliability improvements.

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More data about Duct Calc: HVAC Duct Sizer

Price	Free to download
Total downloads	37
Recent downloads	37
Rating	No ratings
Ranking	Not ranked
Version	1.0.1
APK size	20.8 MB
Number of libraries	?
Suitable for	Everyone
Ads	NO ads

App Performance Report

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Duct Calc: HVAC Duct Sizer compared with similar apps

Common keywords of similar apps

Flex Cfm Offline Free Fully Purchase Data Built Subscription Area Published Compressed Conversion Equivalent Neck Duct Friction Round Calc Sizing Rectangular Diameter Velocity Hvac Size Calculator Rate Airflow Time Pressure

Keywords missing from this app

Calculations App Air Offset Calculate Bend Flow Sheet Standard Users Angle Layout Based Metal Loan Ductwork Industry Drop Recent Cable Design Calculation Pipe Easy Input Sizes System Field Designed Length Added Functions Rebar Manual Ashrae

Downloads over time

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Duct Calc: HVAC Duct Sizer has been downloaded 37 times. Over the past 30 days, it has been downloaded 37 times.

Changelog of Duct Calc: HVAC Duct Sizer

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cleverlywittyapps@gmail.com

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Technologies used by Duct Calc: HVAC Duct Sizer

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