Volumetric flow rate measures the volume of a fluid that passes through a given cross-section per unit of time. In engineering, two of the most common units encountered are the cubic meter per second (m³/s) and the cubic foot per minute (CFM).
Cubic meter per second (m³/s): This is the SI derived unit for volumetric flow rate. It is frequently used in large-scale civil engineering, such as measuring river discharge or the capacity of massive industrial water treatment plants.
Cubic foot per minute (CFM): This is a non-SI unit commonly used in the United States, particularly in HVAC (Heating, Ventilation, and Air Conditioning) systems, pneumatic tools, and compressor specifications.
The conversion between these units is essential when reconciling international equipment specifications with local installation standards. The relationship is defined by the factor \(1 \text{ m}^3/\text{s} \approx 2118.88 \text{ CFM}\).
Cubic meter per second to Cubic foot per minute Conversion Reference Table
Cubic meter per second (m³/s)
Cubic foot per minute (CFM)
0.1
211.888
0.5
1059.44
1.0
2118.88
2.0
4237.76
5.0
10594.4
10.0
21188.8
20.0
42377.6001
50.0
105944.0002
100.0
211888.0004
500.0
1.0594e+06
1000.0
2.1189e+06
Conversion Example: 10 m³/s to CFM
To convert a flow rate from m³/s to CFM, multiply the value by the conversion factor of 2118.880004187246.
CFM is the industry standard in North America for airflow measurement. Because HVAC equipment is often sized based on imperial duct dimensions, CFM provides a more intuitive scale for technicians working with standard ductwork sizes.
The factor 2118.880004187246 is derived from the exact conversion of 1 meter to 3.280839895 feet and 1 second to 1/60 of a minute. For most industrial applications, rounding to two or three decimal places is sufficient.
"On fait la science avec des faits, comme on fait une maison avec des pierres ; mais une accumulation de faits n'est pas plus une science qu'un tas de pierres n'est une maison." "Science is built up of facts, as a house is built of stones; but an accumulation of facts is no more a science than a heap of stones is a house." — Henri Poincaré (French Mathematician, Theoretical Physicist & Mining Engineer)