How this flow rate converter works
Volumetric flow rate measures how much volume of fluid moves past a point each unit of time. It shows up as the liters per minute on a pump, the GPM on an irrigation spec, the cubic meters per hour on a water meter, and the CFM on a fan or compressor. They all measure the same quantity on different scales. To convert accurately between them, this tool turns whatever you type into a single base unit — liters per second (L/s) — and then expresses that base value in every other unit. Converting through a base avoids the rounding errors that creep in when you chain conversions one after another.
The exact factors used (each expressed in liters per second) are: 1 L/min = 1/60 L/s, 1 m³/h = 1000/3600 ≈ 0.277778 L/s, 1 US gal/min (GPM) = 3.785411784/60 ≈ 0.0630902 L/s, 1 US gal/h (GPH) = 3.785411784/3600 ≈ 0.00105150 L/s, and 1 ft³/min (CFM) = 28.316846592/60 ≈ 0.471947 L/s. The most-searched pairings — GPM to L/min and m³/h to GPM — are highlighted at the top so you can read them at a glance.
Common conversions
| From | Equals |
|---|---|
| 1 US gallon per minute (GPM) | 3.785 liters per minute (≈ 0.06309 L/s) |
| 1 liter per second (L/s) | 60 L/min (≈ 15.85 GPM) |
| 1 cubic meter per hour (m³/h) | 4.403 GPM (≈ 16.67 L/min) |
| 1 cubic foot per minute (CFM) | 28.317 liters per minute (≈ 0.4719 L/s) |
| 1 US gallon per hour (GPH) | 0.06309 liters per minute (≈ 0.01667 GPM) |
Reference note: this tool uses US gallons (1 US gal = 3.785411784 L), not imperial (UK) gallons (≈ 4.546 L). CFM is dry volumetric flow and ignores temperature and pressure corrections. Results are rounded for readability.
Frequently asked questions
- How do I convert GPM to L/min?
- Multiply US gallons per minute by 3.785411784 to get liters per minute, because one US gallon is 3.785411784 liters. For example, 10 GPM × 3.785411784 ≈ 37.85 L/min. This converter shows the result instantly the moment you type a value.
- What is CFM?
- CFM stands for cubic feet per minute (ft³/min), a volumetric flow rate used widely for air movement in ventilation, fans, compressors and HVAC. One cubic foot is 28.316846592 liters, so 1 CFM equals about 28.32 liters per minute, or roughly 0.4719 liters per second.
- How many liters per minute is 1 GPM?
- One US gallon per minute equals 3.785411784 liters per minute, usually rounded to 3.785 L/min. In liters per second that is about 0.06309 L/s, and in cubic meters per hour about 0.2271 m³/h.
- What is m³/h?
- Cubic meters per hour (m³/h) is a volumetric flow rate common in water supply, pumps and industrial process specs. One m³/h equals 1,000 liters per hour, or about 0.2778 liters per second, and is roughly 4.4029 US gallons per minute.
- Are US and imperial gallons the same?
- No. This tool uses US gallons, where one US gallon is 3.785411784 liters. An imperial (UK) gallon is larger, at about 4.546 liters, so an imperial GPM is roughly 20 percent more flow than a US GPM. Always check which gallon a spec means.
- Where is flow rate used?
- Volumetric flow rate is used for pumps, plumbing and irrigation (often GPM, L/min or m³/h), and for air handling such as fans, compressors and HVAC (often CFM). Converting between these units lets you compare equipment specs that are quoted in different systems.