Accurate conversion between Litres per Minute (L/min) and Gallons per Minute (GPM)
Convert Litres per Minute to Gallons per Minute instantly with precise calculations. Includes reverse GPM to L/min conversion, full formula reference, real-world flow rate examples, and L/min to GPM conversion tables for 2026.
Professional flow rate conversion for plumbing, hydraulics, irrigation, industrial pumps, and water treatment
Convert Litres per Minute to US Gallons per Minute using the exact defined relationship: 1 US gallon = 3.785411784 litres exactly. Therefore 1 L/min = 0.264172 US GPM. Our tool delivers full-precision results instantly for any flow rate value — from a household tap at 8 L/min through to large industrial pumps rated at thousands of litres per minute.
This converter handles both US GPM (using the US liquid gallon = 3.78541 L) and UK GPM (using the Imperial gallon = 4.54609 L). US GPM is the standard in North America and is used in most international pump and equipment datasheets. UK (Imperial) GPM is used for older British and Australian plumbing specifications. Both results are shown in the output breakdown.
Essential for plumbing and pipe sizing, pump selection, irrigation system design, hydraulic engineering, water treatment plant management, fire suppression systems, industrial process engineering, pool and spa equipment, and HVAC cooling systems in 2026. L/min is the metric standard; GPM dominates pump datasheets in North America — making L/min to GPM one of the most critical flow rate conversions in engineering.
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Litres per minute (L/min) is the standard metric unit for measuring volumetric flow rate — the volume of fluid passing a point per unit of time. It is widely used in Australia, Europe, and Asia for specifying water flow rates in plumbing, pump performance, irrigation, medical gas delivery, fire systems, and industrial process equipment. One litre per minute means exactly one litre of fluid flows past a given point every sixty seconds.
In North America, the equivalent measure is gallons per minute (GPM), which uses the US liquid gallon (3.78541 litres) as its base. Most international pump datasheets, fire suppression standards, and hydraulic system specifications publish flow rates in both L/min and GPM. You can explore more unit converters at the ConcreticMetric converter hub.
The conversion is based on the exact defined volume of the US liquid gallon: 1 US gallon = 231 cubic inches = 3.785411784 litres exactly (since 1964 by international agreement). The Imperial (UK) gallon is defined as 4.54609 litres exactly.
Example: 50 L/min × 0.264172 = 13.209 US GPM
Example: 25 GPM × 3.785412 = 94.635 L/min
Example: 50 L/min × 0.219969 = 10.998 UK GPM
Bar heights represent approximate relative flow rates from household tap to large industrial pump
The reference table below covers the most commonly needed L/min to GPM conversions, from small domestic appliances through to large pumps and industrial flow systems.
| Litres/min (L/min) | US GPM | UK GPM (Imperial) | Real-World Reference |
|---|---|---|---|
| 1 L/min | 0.264 GPM | 0.220 GPM | Slow drip / medical oxygen flow |
| 2 L/min | 0.528 GPM | 0.440 GPM | Drinking water tap (low pressure) |
| 4 L/min | 1.057 GPM | 0.880 GPM | Water-efficient tap (WELS 1 star) |
| 6 L/min | 1.585 GPM | 1.320 GPM | WELS 3-star rated shower |
| 8 L/min | 2.113 GPM | 1.760 GPM | Standard household tap |
| 9 L/min | 2.378 GPM | 1.980 GPM | Average shower head (Australia) |
| 10 L/min | 2.642 GPM | 2.200 GPM | Bath tap — normal flow |
| 15 L/min | 3.963 GPM | 3.300 GPM | Garden hose nozzle |
| 20 L/min | 5.283 GPM | 4.399 GPM | Residential irrigation zone |
| 30 L/min | 7.925 GPM | 6.599 GPM | Small submersible sump pump |
| 50 L/min | 13.209 GPM | 10.998 GPM | Small centrifugal pump |
| 75 L/min | 19.813 GPM | 16.498 GPM | Hot water recirculation system |
| 100 L/min | 26.417 GPM | 21.997 GPM | Commercial irrigation pump |
| 150 L/min | 39.626 GPM | 32.996 GPM | Small fire sprinkler system |
| 200 L/min | 52.834 GPM | 43.994 GPM | Swimming pool circulation pump |
| 300 L/min | 79.251 GPM | 65.991 GPM | Large pool / commercial HVAC |
| 500 L/min | 132.086 GPM | 109.985 GPM | Fire hose / industrial cooling |
| 1,000 L/min | 264.172 GPM | 219.969 GPM | Fire hydrant low pressure |
| 2,000 L/min | 528.344 GPM | 439.938 GPM | Water main branch supply |
| 5,000 L/min | 1,320.860 GPM | 1,099.846 GPM | Large industrial / municipal pump |
Converting L/min to GPM requires knowing which gallon standard is being used. Here is the step-by-step method for both:
The US liquid gallon (3.78541 L) and UK Imperial gallon (4.54609 L) differ by approximately 20%. A pump rated at 100 US GPM delivers only 83.3 UK GPM of the same flow. This 20% difference causes significant errors when comparing pump specifications from American and British/Australian sources without checking which gallon standard is used — always verify before selecting equipment.
Australia's Water Efficiency Labelling and Standards (WELS) scheme rates taps and showers in L/min. A 6-star WELS tap flows at 4 L/min or less (1.06 US GPM). Standard household showers average 9 L/min (2.38 GPM). Water-efficient showerheads achieve 6–7 L/min (1.59–1.85 GPM). Converting these figures to GPM is useful when specifying compatible American-made fittings in Australian plumbing projects.
Fire sprinkler systems are specified in both L/min and GPM depending on the applicable standard. Australian Standard AS 2118 uses L/min; American NFPA 13 uses GPM. A typical residential sprinkler head flows at 40–80 L/min (10.6–21.1 GPM) at design pressure. A fire hydrant capable of 950 L/min (251 GPM) is a common benchmark for urban fire-fighting water supply adequacy.
Pool pump sizing is often specified in GPM in American equipment datasheets but L/min in Australian and European specifications. A standard residential pool of 50,000 litres requires complete turnover in 6–8 hours — meaning a pump flow rate of approximately 104–139 L/min (27.5–36.7 GPM). Converting correctly between L/min and GPM is essential to avoid under-sizing a pool filtration system.
In medical and laboratory settings, gas and liquid flows are measured in L/min with very low values. Oxygen therapy typically flows at 1–6 L/min (0.26–1.59 GPM). Anaesthesia machines deliver precise flows between 0.5–15 L/min. Dialysis machines circulate blood at 200–400 mL/min (0.053–0.106 GPM). These precision applications use L/min exclusively — GPM conversion is only needed when sourcing American-spec replacement components.
Irrigation systems in Australia are designed in L/min, L/hr, and L/s, while American drip and sprinkler equipment is specified in GPM. A typical drip emitter delivers 2–8 L/hr (0.0088–0.035 GPM). A full-coverage overhead sprinkler covers a 6-metre radius at 30–60 L/min (7.9–15.9 GPM). Converting L/min to GPM is essential when importing American irrigation pumps, filters, or controllers for Australian farms.
1 L/min = 0.264172 US GPM = 0.219969 UK GPM
1 US GPM = 3.785412 L/min | 1 UK GPM = 4.54609 L/min
US gallon = 3.78541 L (exact) | UK Imperial gallon = 4.54609 L (exact)
An American pool pump is rated at 35 US GPM. You need to verify it meets the Australian specification of minimum 130 L/min for a 60,000-litre pool with 8-hour turnover.
35 GPM × 3.785412 = 132.49 L/min ✅ — the pump exceeds the minimum requirement by 2.49 L/min.
Never assume "GPM" means US GPM. Older Australian and British plumbing specifications use Imperial (UK) GPM, which is 20.1% larger than US GPM. A pipe spec calling for 50 UK GPM requires 227.3 L/min — but 50 US GPM is only 189.3 L/min. Using the wrong gallon standard when selecting pumps, valves, or meters will cause a significant flow rate error that could result in system underperformance or safety issues.
The Australian Government's Water Efficiency Labelling and Standards (WELS) scheme provides official flow rate ratings in L/min for taps, showers, and appliances. It is the definitive reference for water-efficient product specifications in Australia, with all ratings expressed in litres per minute under AS 6400 test standards in 2026.
Visit WELS →The US National Institute of Standards and Technology documents the exact definition of the US liquid gallon (231 cubic inches = 3.785411784 litres) and the relationship to other volume units. NIST Handbook 44 and SP 811 are the authoritative references for US measurement standards used in pump, pipe, and flow rate specifications throughout North America.
Visit NIST →ConcreticMetric offers free converters for flow rate, volume, pressure, power, force, speed, length, area, energy, and more. All tools are mobile-friendly, free, and built for precision in 2026 — with instant results, full formula references, and real-world worked examples for every conversion type.
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