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GPM to LPM Calculator

Convert flow rate between gallons per minute and liters per minute for pumps and irrigation.

Computed in your browser — nothing you enter is uploaded. Figures are presented for United States against IRC 2024, and every formula is cited under regulatory standards below.

Last verified 2026-08-26 · v1.0.0

Market
Imperial · sales tax

Converted flow rate

37.85 LPM

High confidence

For the dimensions entered, expect a converted flow rate of 37.9 LPM. Note that flow rate sits at the low end of the range this calculator was checked against, so treat the output as indicative rather than settled. Set for United States against IRC 2024. The market selector changes both the units and the code cited.

Add the equipment this sizes

This result is a specification — 37.854 LPM — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.

Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — confirmed fixes become pinned regression tests.

[Schema Verified] Computed in alignment with American Concrete Institute (ACI 318-19) formulas and International Residential Code (IRC 2024) spatial boundaries.

Regulatory standards & verification citations

  • 1 US gallon = 3.78541 liters

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Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.

Frequently asked questions

Where does this come up in plumbing or irrigation work?
Common cases: comparing a US-rated sump pump, well pump, or sprinkler head's GPM spec against a European or metric-labeled product's LPM rating.
Is this the same as GPH (gallons per hour)?
No — GPH is a different time unit. Multiply GPM by 60 to get GPH, or divide GPH by 60 to get GPM, before comparing to an LPM figure if needed.
Does this apply to any liquid?
Yes — this is a pure volumetric flow rate conversion and doesn't depend on what liquid is flowing.