What this converter does
This converter turns cubic feet per minute into cubic metres per hour and back instantly. One CFM is about 1.699 m³/h, the figure used to match US and metric fan or duct ratings. Type a value and read the result as you type.
It also covers litres per second and m³/min. For air speed instead of volume, see the m/s to FPM converter.
The units it covers
These are all volumetric flow-rate units, each with a fixed value in cubic metres per second, so any pair converts through that base.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| Cubic metre per hour | m³/h | 0.0002778 | Metric fan and duct ratings |
| Cubic foot per minute | CFM | 0.0004719 | US fan and duct ratings |
| Litre per second | L/s | 0.001 | Metric ventilation rates |
| Cubic metre per minute | CMM | 0.01667 | Large-volume airflow |
The formula
Each unit has a fixed value in cubic metres per second, so converting between any two is one step:
result = value × factor_from ÷ factor_toWhere:
- value = the number you typed
- factor_from = the “from” unit’s value in m³/s
- factor_to = the “to” unit’s value in m³/s
Worked example
Convert 500 CFM to m³/h.
1 CFM = 1.699011 m³/h500 × 1.699011 = 849.5 m³/hSo 500 CFM equals about 850 m³/h of airflow.
The units in this example
The US airflow rate, standard for fan, duct and ventilation ratings.
- 1 CFM = 1.699 m³/h
- 1 CFM = 0.4719 L/s
- 100 CFM = 169.9 m³/h
- 1 CFM = 0.02832 CMM
The metric airflow rate, standard for fan and duct ratings outside the US.
- 1 m³/h = 0.5886 CFM
- 1 m³/h = 0.2778 L/s
- 1 m³/h = 0.01667 CMM
- 100 m³/h = 58.86 CFM