SettingsSettings for this calculationUS
The flow rate in litres per minute.
Some European data is quoted in litres per second instead — multiply by sixty first. A figure that looks sixty times too small is usually this.
Flow rate
10.04 GPM
1 L = 1/3.785411784 US gallons. Litres per second is a common alternative in European data — multiply by 60 before converting.
- Conversion factor applied
- 0.26 GPM per L/min
They open the calculator with your figures already in it
Litres per Minute to GPM Calculator: 10.04 GPM — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- 1 US gallon = 3.785411784 L, so 1 L/min = 0.264172 GPM
Inputs used
- Flow rate (L/min)
- 38
Intermediate steps
- Conversion factor applied
- 0.26 GPM per L/min
Confidence note: 1 L = 1/3.785411784 US gallons. Litres per second is a common alternative in European data — multiply by 60 before converting.
What this calculation does not cover
- This converts a volume rate and nothing else. It does not check that the flow is deliverable through the pipe you have — bore, velocity limit, available head and fitting losses decide that, and the same litres per minute forced through an undersized run means noise, erosion and outlets starved further down.
- US gallons only. An imperial gallon is about 20% larger, and nothing here can tell which gallon a source figure was written in, so a UK pump curve or an older flow table quoted in "gallons per minute" may not be US gallons at all.
- Gas and compressed air flow is quoted at a stated reference temperature and pressure. The volume arithmetic still holds, but no correction is made for those conditions, so two figures this converts identically can describe different masses of gas.
- It converts exactly the number you type. Data quoted in litres per second is not detected or scaled — you have to multiply by 60 first, and a result that comes out sixty times small is that step being missed.
- A converted flow rate is not a design flow and not an equipment selection. Diversified and simultaneous demand come from fixture-unit tables, and a pump is chosen on flow and head together, never on flow alone.
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This result is a specification — 10.04 GPM — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-02 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- 1 US gallon = 3.785411784 L, so 1 L/min = 0.264172 GPM
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Your workspace
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American pump curves and fixture tables are published in gallons per minute, so metric design figures have to be brought across before equipment can be selected. The arithmetic is straightforward; the reliable source of confusion is which metric unit the original figure uses. European drainage and commercial water design frequently work in litres per second rather than per minute, and a result that comes out sixty times too small is almost always that step being skipped. For gas and compressed air the volume conversion still holds, but the figures are quoted at reference temperature and pressure, so two flow rates in identical units may not describe comparable conditions unless those references match.