Cubic Foot per Minute to Gallon (US) per Hour (CFM to gal/h)
Convert CFM to gal/h — Flow Rate converter
One cubic foot per minute equals 448.831169 gal/h, so to convert cubic feet per minute to gallons (US) per hour you multiply the value by 448.831169. A cubic foot per minute is larger than a gallon (US) per hour — going the other way, 1 gal/h = 0.0022280093 CFM. For example, 10 CFM = 4488.31 gal/h and 50 CFM = 22441.56 gal/h.
1 CFM = 448.831169 gal/h
Cubic Foot per Minute to Gallon (US) per Hour formula
1 Cubic Foot per Minute = 448.831169 gal/h
Worked examples
- 25 CFM = 11220.78 gal/h
- 100 CFM = 44883.12 gal/h
Cubic Foot per Minute to Gallon (US) per Hour conversion table
| Cubic Foot per Minute (CFM) | Gallon (US) per Hour (gal/h) |
|---|---|
| 1 | 448.831169 |
| 2 | 897.662338 |
| 3 | 1346.49 |
| 5 | 2244.16 |
| 8 | 3590.65 |
| 10 | 4488.31 |
| 12 | 5385.97 |
| 15 | 6732.47 |
| 20 | 8976.62 |
| 25 | 11220.78 |
| 50 | 22441.56 |
| 100 | 44883.12 |
| 250 | 112207.79 |
| 500 | 224415.58 |
| 1000 | 448831.17 |
Which gallon, and which trade
The single most expensive mistake in flow conversion is the gallon. A US liquid gallon is 3.785411784 litres; an imperial gallon is 4.54609 litres. US GPM and imperial GPM differ by about 20%, and pump datasheets frequently do not say which one they mean. Check the manufacturer's country of origin before trusting a GPM figure.
Different trades default to different units for the same physical quantity: HVAC and compressed air work in CFM, plumbing and pumps in GPM or LPM, and process and water engineering in m³/h or L/s. A specification that mixes them is usually quoting different equipment, not different flows. On this page, 1 CFM = 448.831169 gal/h.
CFM to metric is worth memorising: one cubic foot is exactly 0.028316846592 m³, so 1 CFM = 1.699011 m³/h and 1,000 CFM ≈ 1,699 m³/h. Note that CFM on a compressor may be quoted as free air delivery (FAD) at inlet conditions rather than at working pressure — the two are not interchangeable.
Frequently asked questions
How many gallons (US) per hour are in one cubic foot per minute?
One cubic foot per minute equals 448.831169 gallons (US) per hour (gal/h).
How many cubic feet per minute are in one gallon (US) per hour?
One gallon (US) per hour equals 0.0022280093 cubic feet per minute (CFM).
How do you convert cubic feet per minute to gallons (US) per hour?
1 Cubic Foot per Minute = 448.831169 gal/h. Use the calculator above for any value.
What is 5 CFM in gal/h?
5 CFM = 2244.16 gal/h.
What is 100 CFM in gal/h?
100 CFM = 44883.12 gal/h.
What is 10 CFM in gal/h?
10 CFM = 4488.31 gal/h.
What is 20 CFM in gal/h?
20 CFM = 8976.62 gal/h.
What is 50 CFM in gal/h?
50 CFM = 22441.56 gal/h.
What is 500 CFM in gal/h?
500 CFM = 224415.58 gal/h.
Is a cubic foot per minute bigger than a gallon (US) per hour?
Yes. A cubic foot per minute is larger — one cubic foot per minute equals 448.831169 gallons (US) per hour (gal/h).