50+ CALCULATORS·FREE · NO SIGN-UP
GPM to LPM Converter — Motion Converter
Flow Rate Converter
Mechanical
0

Formula
01

What this converter does

This converter turns volumetric flow between US gallons per minute, litres per minute, litres per second, cubic metres per hour and cubic feet per minute — instantly and with exact factors. Type a value, pick the units, and the answer updates as you type.

One US gallon per minute equals about 3.785 litres per minute. These figures use the US gallon; the UK gallon is larger. For pumps, pipes and irrigation, GPM ↔ LPM is the everyday pair.

02

The units it covers

Every unit measures volumetric flow, so each converts through the cubic metre per second with a fixed ratio.

View all units & their values
UnitSymbolValueMainly used
US gallon per minuteGPM6.309e-5US pumps, plumbing, irrigation
Litre per minuteLPM1.667e-5Metric pumps, taps, filters
Litre per secondLPS0.001Larger metric flows
Cubic metre per hourm³/h2.778e-4HVAC, water supply, process
Cubic foot per minuteCFM4.719e-4Air and gas flow
03

The formula

Each unit has a fixed value in m³/s, so any conversion goes through it once:

Conversion
result = value × factor_from ÷ factor_to

Where:

  • value = the number you typed, in the “from” unit
  • factor_from = the “from” unit’s value in m³/s
  • factor_to = the “to” unit’s value in m³/s
04

Worked example

Convert 10 GPM to litres per minute.

Step 1 · The factor
1 US GPM ≈ 3.78541 LPM
Step 2 · Multiply
10 × 3.78541 = 37.854 LPM

So 10 US GPM is about 37.9 litres per minute.

05

The units in this example

US gallon per minutesymbol: GPM

A US flow-rate unit — US gallons per minute. Standard for pumps, plumbing and irrigation in the United States.

Common flow conversions
  • 1 GPM ≈ 3.7854 LPM
  • 1 GPM ≈ 0.06309 LPS
  • 1 GPM ≈ 0.2271 m³/h
  • 1 GPM ≈ 0.1337 CFM
Litre per minutesymbol: LPM

A metric flow-rate unit — litres per minute. Common on taps, filters and small metric pumps.

Common flow conversions
  • 1 LPM ≈ 0.2642 GPM
  • 1 LPM = 1/60 LPS
  • 1 LPM = 0.06 m³/h
  • 3.7854 LPM = 1 GPM
06

FAQ

QHow many LPM is 1 GPM?
One US gallon per minute equals about 3.785 litres per minute.
QIs this US or UK gallons?
US gallons. A UK (imperial) gallon is larger, about 4.546 litres.
08

Sources

NIST SP 811 — SI units · Britannica — fluid mechanics

InfoCalculator Editorial Team Fact-checked
Updated Jul 2026 · 3 min read · Reviewed by the InfoCalculator editorial team