maratoolHow to convert GPM to L/min and CFM to m³/h
Type a flow rate — read L/min, GPM, CFM, m³/h, or L/s instantly.
Pumps quote GPM in the US, L/min elsewhere; fans and HVAC quote CFM or m³/h. The Flow Rate Converter converts liquid and air flows through m³/s with exact factors.
How it works
- Pick units — "US gallon per minute (GPM)" to "Liter per minute (L/min)", or any other pair.
- Type a value — the result updates as you type, with swap and copy.
- Copy — one click, with "Copied!" feedback.
Volumetric flow rate conversion factors
Every unit converts through the cubic meter per second (the base unit). To convert A → B, multiply by A's factor and divide by B's:
| Unit | = this many cubic meter per seconds |
|---|---|
| Cubic meter per second (m³/s) | 1 |
| Cubic meter per hour (m³/h) | 0.000277777778 |
| Liter per second (L/s) | 0.001 |
| Liter per minute (L/min) | 1.6667 × 10^-5 |
| Liter per hour (L/h) | 2.7778 × 10^-7 |
| US gallon per minute (GPM) | 6.3090 × 10^-5 |
| US gallon per hour (GPH) | 1.0515 × 10^-6 |
| Cubic foot per minute (CFM) | 0.000471947443 |
| Cubic foot per second (ft³/s) | 0.028316846592 |
When you need it
Handy anchors: 1 GPM = 3.785 L/min, 1 CFM = 1.699 m³/h, and 1 L/s = 3.6 m³/h. A bathroom exhaust fan moves ~50 CFM (85 m³/h); a garden hose flows ~10–17 L/min.
Sources & methodology
Conversion factors follow NIST Special Publication 811; exact-by-definition factors are marked in the tool itself. All math runs client-side in your browser — nothing is uploaded.
More conversion guides
- How to convert mass flow rates (kg/h, lb/h, t/h)
- How to convert liters to gallons, cups, and ounces
- How to convert centistokes to m²/s (kinematic viscosity)
Or browse everything at once in the new unit & sizing converters roundup.