How do I use the Air Flow Calculator?

Enter your values in the fields provided and click Calculate. The air flow calculator will instantly compute results using standard construction formulas and display a detailed breakdown.

What formula does the Air Flow Calculator use?

Airflow is calculated by multiplying the cross-sectional area of the duct (derived from diameter) by the air velocity in feet per minute. Area = π × (diameter/2)² / 144. The formula used is: CFM = Area (ft²) × Velocity (fpm). This formula follows industry-standard construction and engineering practices.

Is the Air Flow Calculator free to use?

Yes, all Calzyra construction calculators are completely free to use. No registration, subscription, or payment is required. All calculations are performed locally in your browser.

Are the results accurate?

Our calculators use industry-standard formulas and are regularly verified for accuracy. Results are estimates and should be verified by a qualified professional for actual construction projects.

Can I use the Air Flow Calculator for professional estimating?

The air flow calculator provides accurate estimates based on the inputs you provide. It is suitable for preliminary planning and estimation. For final project specifications, always consult with licensed professionals and follow local building codes.

Construction CalculatorHVAC

Air Flow Calculator

Calculate the airflow in CFM (Cubic Feet per Minute) based on duct diameter and air velocity. Useful for HVAC duct design and verification.

Updated 2025-01-153 min readCalzyra Construction Team

Calculator

Enter your values below

Duct Diameter (inches)

Air Velocity (fpm)

Formula & Methodology

How this calculator works

CFM = Area (ft²) × Velocity (fpm)

Airflow is calculated by multiplying the cross-sectional area of the duct (derived from diameter) by the air velocity in feet per minute. Area = π × (diameter/2)² / 144.

Frequently Asked Questions

Common questions about this calculator

Air Flow Calculator

Calculator

Formula & Methodology

About Air Flow Calculator

Frequently Asked Questions

Air Flow Calculator

Calculator

Formula & Methodology

About Air Flow Calculator

Frequently Asked Questions