Flow rate (volume) converter
Volumetric flow for pumps, pipes, HVAC and process plant. US and imperial gallons per minute differ by about 20%, so both are labelled.
US customary and British imperial units with the same name differ in size. Each is labelled US or UK in the unit list.
1 US gallon per minute = 3.7854 litres per minute
How it’s calculated
L/min = gpm (US) × 3.785411784
- Multiply the value in US gallons per minute by 3.785411784.
- To go back, divide by 3.785411784 (or multiply by 0.2641720524).
- 1 gpm (US) = 3.785411784 L/min · 1 L/min = 0.2641720524 gpm (US)
Show worked solutionFactor, unit cancellation and rounding, step by step
Find the conversion factor
By definition 1 gpm (US) = 0.0000630901964 m³/s and 1 L/min = 0.0000166666666666667 m³/s, so 1 gpm (US) = 3.785411784 L/min. Source: NIST SP 811 / Handbook 44; BIPM SI Brochure (9th ed.) (SI prefixes and accepted units).
Multiply by the factor written as a fraction
Put gpm (US) in the denominator so it cancels, leaving L/min.
Calculate (unrounded)
Round the answer
Rounded to 5 significant figures.
Answer: 3.7854 L/min
1 gpm (US) in other units
Batch convert gpm (US) → L/min
- 1 gpm (US) = 3.7854 L/min
- 5 gpm (US) = 18.927 L/min
- 10 gpm (US) = 37.854 L/min
- 25 gpm (US) = 94.635 L/min
Common flow rate (volume) conversions
Flow rate (volume) units and exact definitions
| Unit | System | Definition |
|---|---|---|
| Cubic metre per second (m³/s) | SI (metric) | Base unit |
| Cubic metre per hour (m³/h) | metric (non-SI) | 1 m³/h = 0.0002777777778 m³/s |
| Cubic metre per minute (m³/min) | metric (non-SI) | 1 m³/min = 0.01666666667 m³/s |
| Litre per second (L/s) | metric (non-SI) | 1 L/s = 0.001 m³/s |
| Litre per minute (L/min) | metric (non-SI) | 1 L/min = 0.00001666666667 m³/s |
| Litre per hour (L/h) | metric (non-SI) | 1 L/h = 2.777777778e-7 m³/s |
| Millilitre per minute (mL/min) | metric (non-SI) | 1 mL/min = 1.666666667e-8 m³/s |
| US gallon per minute (gpm (US)) | US customary | 1 gpm (US) = 0.0000630901964 m³/s |
| Imperial gallon per minute (gpm (UK)) | British imperial | 1 gpm (UK) = 0.00007576816667 m³/s |
| US gallon per hour (gph (US)) | US customary | 1 gph (US) = 0.000001051503273 m³/s |
| Cubic foot per minute (cfm) | US & imperial (identical) | 1 cfm = 0.0004719474432 m³/s |
| Cubic foot per second (ft³/s) | US & imperial (identical) | 1 ft³/s = 0.02831684659 m³/s |
| Oil barrel per day (bbl/d) | US customary | 1 bbl/d = 0.000001840130728 m³/s |
US gallons per minute to litres per minute conversion table
| US gallons per minute (gpm (US)) | Litres per minute (L/min) |
|---|---|
| 0.1 gpm (US) | 0.37854 L/min |
| 0.5 gpm (US) | 1.8927 L/min |
| 1 gpm (US) | 3.7854 L/min |
| 2 gpm (US) | 7.5708 L/min |
| 3 gpm (US) | 11.356 L/min |
| 4 gpm (US) | 15.142 L/min |
| 5 gpm (US) | 18.927 L/min |
| 6 gpm (US) | 22.712 L/min |
| 7 gpm (US) | 26.498 L/min |
| 8 gpm (US) | 30.283 L/min |
| 9 gpm (US) | 34.069 L/min |
| 10 gpm (US) | 37.854 L/min |
| 15 gpm (US) | 56.781 L/min |
| 20 gpm (US) | 75.708 L/min |
| 25 gpm (US) | 94.635 L/min |
| 30 gpm (US) | 113.56 L/min |
| 40 gpm (US) | 151.42 L/min |
| 50 gpm (US) | 189.27 L/min |
| 75 gpm (US) | 283.91 L/min |
| 100 gpm (US) | 378.54 L/min |
| 250 gpm (US) | 946.35 L/min |
| 500 gpm (US) | 1,892.7 L/min |
| 1,000 gpm (US) | 3,785.4 L/min |
Frequently asked questions
Which flow rate (volume) units can I convert?
cubic metres per second (m³/s), cubic metres per hour (m³/h), cubic metres per minute (m³/min), litres per second (L/s), litres per minute (L/min), litres per hour (L/h), millilitres per minute (mL/min), US gallons per minute (gpm (US)), imperial gallons per minute (gpm (UK)), US gallons per hour (gph (US)), cubic feet per minute (cfm), cubic feet per second (ft³/s), oil barrels per day (bbl/d).
How accurate are the results?
Every unit is stored with its exact defining factor (NIST SP 811, NIST Handbook 44 or the BIPM SI Brochure). Calculations use double-precision arithmetic and are rounded only for display, to 5 significant figures by default (trailing zeros dropped, so 1 km shows as 1000 m). You can choose Auto (up to 10 digits), fixed decimals or more significant figures, or switch to scientific or engineering notation.
Why do US and UK (imperial) units give different answers?
Several units share a name but not a size. A US gallon is exactly 3.785411784 L while an imperial gallon is exactly 4.54609 L; a US fluid ounce is about 29.57 mL and a UK fluid ounce about 28.41 mL. Units are labelled US or UK throughout so you can pick the right one.