What is the exact conversion factor from GPM to L/min?

1 US gallon per minute equals exactly 3.785411784 liters per minute. This derives from the definition of the US liquid gallon as exactly 3.785411784 liters.

Is this for US gallons or UK (Imperial) gallons?

This converter uses US liquid gallons (the standard GPM used in North American pump and flow rate specifications). 1 UK imperial gallon = 4.54609 liters, so UK GPM to L/min uses a different factor.

How do I convert L/min back to GPM?

Divide the liters per minute value by 3.785411784. The reverse converter on this page does this automatically.

Why do pump manufacturers use GPM while metric specs use L/min?

GPM is the dominant unit in US and Canadian engineering standards (ANSI/ASME), while L/min is used under ISO and metric building codes. Equipment shipped globally often lists both.

What flow rate is typical for a household well pump?

Residential well pumps typically deliver 5–25 GPM (19–95 L/min). A 10 GPM pump outputs about 37.85 L/min.

GPM to L/min Converter

Name: GPM to L/min Converter
Availability: InStock
Author: Nham Vu

Enter a flow rate in US gallons per minute (GPM) and get the equivalent in liters per minute (L/min) instantly.

Convert GPM → L/min

Gallons per minute (GPM)

Common presets

Convert L/min → GPM

Liters per minute (L/min)

Common presets

GPM to L/min Reference Table

GPM	L/min	Common application
0.5	1.893	Low-flow drip irrigation head
1	3.785	Shower head (low-flow)
2.5	9.464	Standard shower head (US)
10	37.854	Residential well pump (small)
25	94.635	Residential well pump (large)
100	378.541	Light commercial irrigation
500	1,892.706	Industrial process pump
1,000	3,785.412	Municipal water main segment

Summary

Enter a flow rate in US gallons per minute (GPM) and get the equivalent in liters per minute (L/min) instantly.

How it works

Enter a flow rate value in US gallons per minute (GPM).
The converter multiplies by the exact factor 3.785411784 to produce liters per minute.
The result appears instantly below the input field.
Use the reverse converter to go from L/min back to GPM.
Switch between common pump flow rate presets for quick reference.

Use cases

Select the right pump by matching GPM ratings to metric L/min specs.
Convert irrigation system flow rates from US to metric units.
Verify industrial fluid system capacities across unit standards.
Compare fire suppression system output between US and metric specs.
Convert pool or spa circulation pump ratings for international equipment.
Cross-check HVAC chilled water flow rates in metric building codes.

Frequently Asked Questions

Last updated: 2026-07-22 · Reviewed by Nham Vu