HVAC & Airflow

CMH to CFM Calculator

Cubic metres per hour to CFM.

Enter your values

Enter the airflow in CMH.

Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.

Results
Airflow
294.3 CFM
In L/s
138.9
In CMM
8.33
In CMH
500

Quick answer

One cubic metre per hour equals 0.588578 CFM.

CFM = CMH x 0.588578

At a glance

What it doesCubic metres per hour to CFM.
CategoryHVAC & Airflow
Inputs neededAirflow
Main outputAirflow
FormulaCFM = CMH x 0.588578
CostFree — no sign-up, no download

How to use the CMH to CFM Calculator

  1. 1Enter the metric airflow in CMH.
  2. 2Read the CFM equivalent.
  3. 3Cross-check L/s if your code uses it.

Inputs explained

Airflow(CMH)
Enter the airflow in CMH.

Worked example

Using the values the calculator loads with:

Inputs

  • Airflow500 CMH

Results

  • Airflow294.3 CFM
  • In L/s138.9
  • In CMM8.33
  • In CMH500

Frequently asked questions

Why do specs differ so much?

Free-air ratings ignore duct resistance; installed airflow is usually 20-40% lower.

Rounding?

Using 0.59 is accurate to within a fifth of a percent.

What do I need to enter into the CMH to CFM Calculator?

Just 1 value: airflow. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.

How does the CMH to CFM Calculator work out the answer?

One cubic metre per hour equals 0.588578 CFM. It applies the formula CFM = CMH x 0.588578 and shows the working so you can check each step by hand.

Is the CMH to CFM Calculator free, and do I need an account?

It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.

Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.