Litres per Minute to Gallons per Hour Converter
Convert a flow rate in L/min into UK or US gallons per hour, with run-time volume, tank fill time and reverse flow checks.
Flow Rate Inputs
Gallons per Hour Result
This is a flow-rate conversion. It does not account for pipe losses, pump head, filters, hose length or falling tank pressure.
What This Flow Converter Is For
Litres per minute is a common flow rate on pump labels, shower test notes, garden irrigation checks, pond filters, transfer pumps, caravan pumps and workshop equipment. Gallons per hour appears on older manuals, imported pumps, aquarium equipment and some irrigation notes. This page converts the rate directly and then adds practical checks so the number is easier to use: how much water moves during a timed run, how long a vessel may take to fill and what the equivalent daily flow would be if the equipment runs for only part of the time.
The converter asks for the gallon system because UK and US gallons differ. The UK imperial gallon is larger, so a given L/min flow produces fewer UK gallons per hour than US gallons per hour. If you are comparing a UK pump with a US aquarium filter, select the same gallon system as the document you are reading before comparing capacities.
Flow Rate Example For A Pump Check
Starting Flow
A pump measured at 25 L/min converts to about 329.9 UK gal/hour. The same physical flow is about 396.3 US gal/hour, so the stated gallon type changes the published-looking value.
Timed Run
Over 45 minutes, 25 L/min moves 1,125 litres before losses. If the hose rises to a higher outlet or passes through a filter, the actual delivered volume may be lower.
Tank Fill
A 1,000 litre tank would take about 40 minutes at the entered rate. In practice, air locks, float valves, pump cut-out and the final few litres can slow the last part of filling.
Duty Cycle
At 100 percent duty, the effective daily volume is 36,000 litres. At 25 percent duty, the same pump would run for six hours in a day and move about 9,000 litres.
Conversion Formula And Method
The unit conversion is stable because litres, minutes, hours and gallon sizes are defined units. The practical lines are estimates based on the entered flow rate staying constant.
Litres per hour = litres per minute x 60
UK gallons per hour = litres per minute x 60 / 4.54609
US gallons per hour = litres per minute x 60 / 3.785411784
Gallons per minute = gallons per hour / 60
Run volume in litres = litres per minute x run time in minutes
Fill time in minutes = vessel litres / litres per minute
Effective daily litres = litres per minute x 60 x 24 x duty cycle percent / 100
Use the converted value for unit comparison, capacity planning and quick equipment checks. For pump sizing, you also need head height, pipe bore, bends, strainers, valves, fluid temperature, solids content and manufacturer curves. A pump that can move 60 L/min at zero head may not move 60 L/min through a long hose to a raised tank.
Common L/min To Gallons per Hour Values
| L/min | UK gal/hour | US gal/hour | Litres/hour | Typical Reading |
|---|---|---|---|---|
| 1 | 13.2 | 15.9 | 60 | Small dosing, drip or low-flow test value. |
| 5 | 66.0 | 79.3 | 300 | Small pump, light transfer or restricted outlet. |
| 10 | 132.0 | 158.5 | 600 | Common domestic or garden comparison value. |
| 25 | 329.9 | 396.3 | 1,500 | Useful for transfer pumps and larger hose checks. |
| 50 | 659.9 | 792.5 | 3,000 | Higher-flow pump; pipe losses matter more. |
| 100 | 1,319.8 | 1,585.0 | 6,000 | Large pump territory; use a pump curve for real sizing. |
Measuring A Real Flow Rate
If you are checking an installed pump, a bucket test can be more useful than the label rating. Use a container of known size, time how long it takes to fill at the normal outlet and convert the measured litres and seconds into L/min. Repeat the test if the pump cycles, surges or draws from a low tank. For high flows, use a larger container or a flow meter so the timing error does not dominate the result.
Before You Rely On The Result
- Check whether the manual uses UK or US gallons.
- Measure flow at the outlet you actually use, not at the pump body.
- Run one case for clean filters and another after the filter has started to restrict flow.
- For drinking-water systems, follow plumbing, water-quality and backflow rules rather than relying on a unit conversion.
- For aquarium and pond equipment, compare flow with the filter manufacturer’s turnover guidance and livestock needs.
When a label gives a maximum open-flow rating, run a second calculation with a lower measured value. A small submersible pump might be advertised at 1,500 L/hour, but the outlet height, pipework and filter can reduce the delivered flow. If the measured rate is 18 L/min rather than 25 L/min, the UK gallons per hour result falls from about 329.9 to about 237.6. That difference matters for tank filling, water changes, irrigation timing and any process where the pump runs for a set number of minutes. For repeated jobs, write down the measured outlet, hose length and container size with the converted result so the next check is comparable. If the liquid is not water, note its temperature and viscosity as well. Re-test after cleaning filters, changing hose, or raising the outlet height. Record the test date too. Keep notes.
FAQs
How many UK gallons per hour is 1 L/min?
1 L/min is about 13.20 UK gallons per hour. The US value is about 15.85 US gallons per hour because the US gallon is smaller.
Why does the answer change when I switch gallon type?
The litres and time do not change. Only the size of the gallon changes. A larger UK gallon means fewer gallons for the same volume of water.
Can I use this for litres per second?
Convert litres per second to litres per minute first by multiplying by 60. Then enter the L/min value. For example, 0.5 L/s is 30 L/min.
Does this calculate pump head loss?
No. It is a unit and planning converter. Pump head loss depends on height, pipe bore, length, fittings, valves, strainers, fluid properties and pump design.
What is duty cycle?
Duty cycle is the percentage of the day the equipment is assumed to run. A 50 percent duty cycle means the converter treats the flow as running for 12 hours in 24.
Can I use it for fuel or chemicals?
The arithmetic works for any liquid volume unit, but safety, density, compatibility and handling rules differ. For fuels and chemicals, use suitable equipment and product-specific guidance.
Sources
Bureau International des Poids et Mesures. (2019). The International System of Units (SI Brochure). BIPM. https://www.bipm.org/en/publications/si-brochure
National Institute of Standards and Technology. (2008). Guide for the Use of the International System of Units (NIST Special Publication 811). NIST. https://www.nist.gov/pml/special-publication-811
Water Regulations Advisory Scheme. (n.d.). Water Regulations Guidance. WRAS. https://www.wrasapprovals.co.uk/resources/