What this converter does
This converter turns US gallons per minute into litres per second and back instantly. It also covers litres per minute, cubic metres per hour and imperial GPM — every pair uses an exact fixed factor. Type a flow, pick your units, and read the result as you type.
One US gallon per minute equals about 0.0631 litres per second. Flow rate sets pump duty and pipe size, so getting the units right matters for plumbing and fire-protection design.
The units it covers
Every unit measures volume flow, so each converts through the litre per second with a fixed ratio.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| US gallon per minute | GPM | 0.06309 | US plumbing & pump flow |
| Litre per second | L/s | 1 | SI flow — pipe & pump sizing |
| Litre per minute | L/min | 0.01667 | Taps, fixtures, small flows |
| Cubic metre per hour | m³/h | 0.2778 | Water mains, large systems |
| Imperial gallon per minute | IGPM | 0.07577 | UK plumbing flow |
The formula
Each unit has a fixed value in litres per second, so converting between any two means going through L/s once:
result = value × factor_from ÷ factor_toWhere:
- value = the flow you typed, in the “from” unit
- factor_from = the “from” unit’s value in L/s
- factor_to = the “to” unit’s value in L/s
Worked example
Convert 50 GPM to litres per second.
1 GPM = 0.0630902 L/s50 × 0.0630902 = 3.155 L/sSo 50 US gallons per minute is about 3.15 litres per second.
The units in this example
The US customary flow unit for pumps, fixtures and fire flow. One US gallon is 3.785 litres.
- 1 GPM = 0.0631 L/s
- 1 GPM = 3.785 L/min
- 1 GPM = 0.227 m³/h
- 1 GPM ≈ 0.833 imperial GPM
The SI-based flow unit used for pipe and pump sizing in most of the world.
- 1 L/s = 15.85 GPM
- 1 L/s = 60 L/min
- 1 L/s = 3.6 m³/h
- 1 L/s = 1,000 mL/s