Flow rate measures the volume of fluid that passes through a specific point within a given time frame, commonly used units include cubic meters per hour (m³/hr), liters per minute (L/min), gallons per minute (GPM) for the U.S. customary system, and cubic feet per hour (ft³/hr).
| LPS (l/sec) | LPM (l/min) | CMH (m3/hr) | CFM (ft3/min) | CFH (ft3/hr) | GPM (gal/min) | |
| 1 LPS (l/sec) | 1 | 60 | 3.6 | 2.119 | 127.1 | 15.85 |
| 1 LPM (l/min) | 0.01667 | 1 | 0.06 | 0.03532 | 2.119 | 0.02642 |
| 1 CMH (m3/hr) | 0.2778 | 16.67 | 1 | 0.589 | 35.32 | 4.403 |
| 1 CFM (ft3/min) | 0.472 | 28.32 | 1.7 | 1 | 60 | 7.48 |
| 1 CFH (ft3/hr) | 7.87×10-3 | 0.472 | 0.02832 | 0.01667 | 1 | 0.1247 |
| 1 GPM (gal/min) | 0.0631 | 3.785 | 0.2271 | 0.1337 | 8.021 | 1 |
