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LPS to GPM Converter — Water Converter
Water Flow Converter
Plumbing
0

Formula
01

What this converter does

This converter turns litres per second into US gallons per minute 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 litre per second equals about 15.85 US gallons per minute. Use it to convert metric pump and pipe flows into the US units on many fixtures and fire-flow tables.

02

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
UnitSymbolValueMainly used
US gallon per minuteGPM0.06309US plumbing & pump flow
Litre per secondL/s1SI flow — pipe & pump sizing
Litre per minuteL/min0.01667Taps, fixtures, small flows
Cubic metre per hourm³/h0.2778Water mains, large systems
Imperial gallon per minuteIGPM0.07577UK plumbing flow
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The formula

Each unit has a fixed value in litres per second, so converting between any two means going through L/s once:

Conversion
result = value × factor_from ÷ factor_to

Where:

  • 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
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Worked example

Convert 5 litres per second to GPM.

Step 1 · The factor
1 L/s = 15.8503 GPM
Step 2 · Multiply
5 × 15.8503 = 79.25 GPM

So 5 litres per second is about 79 US gallons per minute.

05

The units in this example

Litre per secondsymbol: L/s

The SI-based flow unit used for pipe and pump sizing in most of the world.

Common flow conversions
  • 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
US gallon per minutesymbol: GPM

The US customary flow unit for pumps, fixtures and fire flow. One US gallon is 3.785 litres.

Common flow conversions
  • 1 GPM = 0.0631 L/s
  • 1 GPM = 3.785 L/min
  • 1 GPM = 0.227 m³/h
  • 1 GPM ≈ 0.833 imperial GPM
06

FAQ

QHow many GPM is 1 litre per second?
One litre per second equals about 15.85 US gallons per minute.
QWhy convert L/s to GPM?
Metric pump ratings are in L/s, but many US fixtures and fire-flow tables use GPM.
08

Sources

USGS — measuring water flow · NIST SP 811 — SI units

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