GPM to LPM Converter
1 US gallon equals 3.785412 liters. To convert from GPM to LPM, multiply by 3.785412. The US gallon is smaller than the Imperial (UK) gallon, which is 4.54609 liters. This...
Formula
Source: NIST | Last reviewed: June 7, 2026
Examples
1 GPM (US)
= 3.785 L/min
1 US GPM = 3.785 LPM
10 GPM (US)
= 37.85 L/min
100 GPM (US)
= 378.5 L/min
1000 GPM (US)
= 3785 L/min
Quick Reference Table
| GPM | LPM |
|---|---|
| 1 | 3.79 |
| 5 | 18.93 |
| 10 | 37.85 |
| 20 | 75.71 |
| 50 | 189.27 |
| 100 | 378.54 |
Where is this used?
HVAC chilled water systems, process pumps, irrigation.
Frequently Asked Questions
Is GPM the same as US GPM and Imperial GPM?
No. GPM in the US almost always means US GPM (1 gal = 3.785 L). UK/imperial GPM is 4.546 L/min, about 20% larger. This converter uses US GPM.
How do I convert LPM to m³/h?
Multiply LPM by 0.06. So 100 LPM = 6 m³/h.
What's the difference between GPM and CFM?
GPM measures liquid volume flow (gallons per minute of water or another fluid). CFM measures gas volume flow (cubic feet per minute of air). They are not directly interchangeable — you'd need density and unit conversions.
Reviewed for accuracy
· Last reviewed: June 7, 2026
All calculations are for reference only. Always verify with manufacturer data and a qualified engineer for critical applications. Learn about our editorial process.