The litre per minute is a unit of volumetric flow rate equal to one litre passing a point every minute. Its symbol is L/min. It is the unit of taps, showers and small pumps — the flows a person meets directly, at a rate slow enough that a minute is the natural interval to count over.
Household plumbing is specified in it almost everywhere. A modern shower head delivers 6 to 9 litres per minute, an older one 15 or more, a kitchen tap 5 to 10, and a bath filler 15 to 20. Water-efficiency regulations in many countries set maximum figures in exactly these terms, because the flow rate multiplied by a typical shower length gives the volume of water and the energy needed to heat it.
That calculation is the reason the unit matters beyond plumbing. Reducing a shower from 12 to 8 litres per minute cuts both the water and the heating energy by a third, and heating water is one of the largest energy uses in a house. A restrictor costing very little changes a household's energy bill measurably.
Medicine uses the unit for gases. Oxygen therapy is prescribed in litres per minute — 2 through a nasal cannula for mild supplementation, 15 through a mask with a reservoir in an emergency — and the flowmeter on the wall of a hospital room is calibrated in exactly this unit. Anaesthetic machines are set the same way.
Engines and compressors also appear here. A small air compressor delivers 100 to 200 litres per minute of free air; a car's cooling system circulates tens of litres per minute; a garden pump moves 20 to 60. In each case the number is the useful one because the equipment runs for minutes at a time rather than seconds.
Sixty litres per minute is one litre per second, so the two units differ by the same factor as the two time units. That makes the conversion easy to do mentally, and it explains why the same equipment is often described in litres per minute by its manufacturer and litres per second by the engineer designing the system it goes into.
One litre per minute equals about 0.01667 litres per second, 1,000 millilitres per minute, or about 0.22 imperial gallons per minute.
| Unit | Symbol | 1 Liter per minute equals | 1 of these equals | Converter |
|---|---|---|---|---|
| Milliliter per second | mL/s | 16.6666666667 mL/s | 0.06 L/min | Liters per minute to Milliliters per second |
| Milliliter per minute | mL/min | 1000 mL/min | 0.001 L/min | Liters per minute to Milliliters per minute |
| Milliliter per hour | mL/h | 60000 mL/h | 0.0000166666666667 L/min | Liters per minute to Milliliters per hour |
| Liter per second | L/s | 0.0166666666667 L/s | 60 L/min | Liters per minute to Liters per second |
| Liter per hour | L/hour | 60 L/hour | 0.0166666666667 L/min | Liters per minute to Liters per hour |
| Cubic millimeter per second | mm³/s | 16666.6666667 mm³/s | 0.00006 L/min | Liters per minute to Cubic millimeters per second |
| Cubic millimeter per minute | mm³/min | 1000000 mm³/min | 0.000001 L/min | Liters per minute to Cubic millimeters per minute |
| Cubic millimeter per hour | mm³/hour | 60000000 mm³/hour | 0.0000000166666666667 L/min | Liters per minute to Cubic millimeters per hour |
| Cubic centimeter per second | cm³/s | 16.6666666667 cm³/s | 0.06 L/min | Liters per minute to Cubic centimeters per second |
| Cubic centimeter per minute | cm³/min | 1000 cm³/min | 0.001 L/min | Liters per minute to Cubic centimeters per minute |
| Cubic centimeter per hour | cm³/h | 60000 cm³/h | 0.0000166666666667 L/min | Liters per minute to Cubic centimeters per hour |
| Cubic meter per second | m³/s | 0.0000166666666667 m³/s | 60000 L/min | Liters per minute to Cubic meters per second |
| Cubic meter per minute | m³/min | 0.001 m³/min | 1000 L/min | Liters per minute to Cubic meters per minute |
| Cubic meter per hour | m³/h | 0.06 m³/h | 16.6666666667 L/min | Liters per minute to Cubic meters per hour |
| Cubic inch per second | in³/s | 1.01706240158 in³/s | 0.98322384 L/min | Liters per minute to Cubic inches per second |
| Cubic inch per minute | in³/min | 61.0237440947 in³/min | 0.016387064 L/min | Liters per minute to Cubic inches per minute |
| Cubic inch per hour | in³/h | 3661.42464568 in³/h | 0.000273117733333 L/min | Liters per minute to Cubic inches per hour |
| Cubic foot per second | ft³/s | 0.000588577778733 ft³/s | 1699.0107954 L/min | Liters per minute to Cubic feet per second |
| Cubic foot per minute | ft³/min | 0.035314666724 ft³/min | 28.31684659 L/min | Liters per minute to Cubic feet per minute |
| Cubic foot per hour | ft³/h | 2.11888000344 ft³/h | 0.471947443167 L/min | Liters per minute to Cubic feet per hour |
| Fluid ounce per second | fl oz/s | 0.586584662131 fl oz/s | 1.70478375 L/min | Liters per minute to Fluid ounces per second |
| Fluid ounce per minute | fl oz/min | 35.1950797279 fl oz/min | 0.0284130625 L/min | Liters per minute to Fluid ounces per minute |
| Fluid ounce per hour | fl oz/h | 2111.70478367 fl oz/h | 0.000473551041667 L/min | Liters per minute to Fluid ounces per hour |
| Gallon per second | gal/s | 0.00366615413832 gal/s | 272.7654 L/min | Liters per minute to Gallons per second |
| Gallon per minute | gal/min | 0.219969248299 gal/min | 4.54609 L/min | Liters per minute to Gallons per minute |
| Gallon per hour | gal/h | 13.1981548979 gal/h | 0.0757681666667 L/min | Liters per minute to Gallons per hour |
| US Gallon per second | gal US/s | 0.0044028675393 gal US/s | 227.12470704 L/min | Liters per minute to US Gallons per second |
| US Gallon per minute | gal US/min | 0.264172052358 gal US/min | 3.785411784 L/min | Liters per minute to US Gallons per minute |
| US Gallon per hour | gal US/h | 15.8503231415 gal US/h | 0.0630901964 L/min | Liters per minute to US Gallons per hour |