Convert m³/h to L/min cubic metres per hour ↔ litres per minute Free Online Secure
Type a value in cubic metres per hour and read it in litres per minute at once. The factor is exact by definition, the arithmetic happens in your browser, and nothing is sent anywhere.
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Convert to litres per minute
Common values — Convert m³/h to L/min (cubic metres per hour ↔ litres per minute)
| m³/h | L/min |
|---|---|
| 1 | 16.6666666667 |
| 2 | 33.3333333333 |
| 3 | 50 |
| 5 | 83.3333333333 |
| 10 | 166.666666667 |
| 20 | 333.333333333 |
| 50 | 833.333333333 |
| 100 | 1666.66666667 |
Where these units come from
Flow rate has no unit of its own either: it is a volume divided by a time, so each trade kept the volume it already used and attached whichever time suited the scale of the job. Litres per minute came from taps, pumps and anything a person watches fill; cubic metres per hour from water utilities, ventilation and irrigation, where a minute is too short to be useful; US gallons per minute from American plumbing, fire codes and well pumps. The numbers look very different for the same stream — one litre per minute is 0.06 cubic metres per hour — which is why a pump quoted in one unit and a pipe sized in another is a common source of expensive mistakes.
Where you meet them
A shower head delivers around 9 litres per minute, a garden hose roughly twice that, a domestic boiler is rated by how many litres a minute it can raise by a given temperature. Cubic metres per hour price water, size ventilation ducts and rate industrial pumps. Gallons per minute appear on American pump labels, sprinkler systems and fire hydrant specifications.
Questions people ask
Which gallon does gallons per minute mean here?
The US gallon, 3.785411784 litres. An imperial gallon per minute would be about a fifth larger, so a British figure quoted in gpm and read as American understates the flow by about a sixth. Pump and sprinkler data sheets rarely say which they mean, so check the country of origin before trusting a conversion in either direction.
Is a higher flow rate the same as higher pressure?
No, and confusing them is how showers get ruined. Pressure is the push; flow is how much actually moves. A narrow pipe at high pressure can deliver less water than a wide pipe at low pressure. Pumps are specified by both together — a curve showing what flow they achieve at each pressure — because neither number means much on its own.
Is the answer exact?
Where both units are defined in terms of one another by whole numbers, yes — the page says so above the figure, and the only rounding is in how many digits are shown. Where the ratio has no finite decimal, the page shows twelve significant digits and says the relation is approximate rather than pretending otherwise.
Does anything I type leave my device?
No. The arithmetic runs in your browser; nothing is uploaded and there is no server to upload it to. Load the page once and it keeps working with the network switched off.
Cubic metres per hour to litres per minute: air, gas and heating water in building services
Building-services engineers deal with three fluids in a house or an office: air, gas and water. Air handlers and fans are rated in cubic metres per hour, gas meters carry a maximum in cubic metres per hour, and circulation pumps are chosen in cubic metres per hour too. Yet a plumber, a ventilation technician or a person reading a boiler plate often thinks in litres per minute, and the two worlds meet when someone asks how large a duct or a pipe must be. To convert m³/h to L/min, multiply by 16.67: 1 m³/h is 16.7 L/min, 6 m³/h is 100 L/min and 600 m³/h is 10,000 L/min. The calculator above multiplies as you type, and the sections that follow show what the figures mean for ventilation, gas supply and hydronic heating.
Below come the rule with examples, short notes on each unit, a side-by-side look and a long series of building-services cases, ending with the slips people make most. Everything is computed locally in the page. Gas and ventilation design is regulated work and belongs to qualified engineers.
How to convert m³/h to L/min: multiply by 16.67
The rule
There are 1,000 litres in a cubic metre and 60 minutes in an hour, which makes one cubic metre an hour equal to 1,000 / 60 = 16.667 litres a minute. For a “convert m³/h to L/min” calculation, take the m³/h figure times 16.67: 2 m³/h gives 33.3 L/min, 15 m³/h gives 250 L/min and 90 m³/h gives 1,500 L/min. To go the other way, multiply L/min by 0.06.
Worked examples
A domestic gas meter of size G4 passes at most 6 m³/h, 100 L/min. A bathroom extract fan of 54 m³/h moves 900 L/min. A heat-pump circuit of 1.72 m³/h carries 28.7 L/min. A kitchen hood of 600 m³/h extracts 10,000 L/min.
Air, gas and water alike
The conversion does not depend on the fluid. It works for a litre of air, gas or water, though the amount of heat or energy in a litre differs enormously between them. A cubic metre of water holds 1,163 Wh of heat per kelvin, a cubic metre of air only 0.33.
A quick sanity test
Expect the L/min result to be about seventeen times the m³/h figure. A smaller number than you began with means 0.06 was used where 16.67 belonged.
Cubic metres per hour
The unit of building services
Designers rate fans, gas meters, filters and pumps in cubic metres per hour. The unit suits flows of tens to thousands, and it matches the way meter plates and fan curves are drawn.
Where it appears
Ventilation schedules, gas meter plates, pump curves and air-handling units.
Litres per minute
The unit of the bench and the tap
Litres per minute are easier to picture: a bucket of 10 litres filled in 15 seconds. They are used for fixtures, small pumps, test equipment and the breathing of a person on exercise.
Where it appears
Taps, showers, test benches, medical devices and small appliances.
m³/h against L/min
Counted in litres per minute, a flow looks about seventeen times bigger than in cubic metres per hour: 9 m³/h turns into 150 L/min and 36 m³/h into 600 L/min. The air, gas or water is the same, and only the yardstick changes.
Nothing is lost on the way. The mistake that shows up most is mixing m³/h with L/s and L/min, which are 3.6 and 16.67 apart.
Where the conversion shows up
Ventilation
Fresh air for people is set at 25 m³/h each, 417 L/min or 7 L/s. An office of ten people needs 250 m³/h, 4,170 L/min. Bathrooms are extracted at about 54 m³/h, 15 L/s, 900 L/min, and a WC at 22 m³/h, 6 L/s, 360 L/min. A kitchen hood of 600 m³/h, 167 L/s, extracts 10,000 L/min. A “convert m³/h to L/min” calculation puts the schedule into a form a site team can check with an anemometer.
Gas supply
A gas boiler of 24 kW burning gas of 10.5 kWh/m³ uses 2.3 m³/h, 38 L/min. A hob of 3 kW uses 0.29 m³/h, 4.8 L/min. The G4 meter in a house passes 6 m³/h, 100 L/min, which is 63 kW of gas, enough for a boiler and a cooker together.
Hydronic heating
The flow in a heating circuit is the heat in kW divided by 1.163 times the temperature drop. A heat pump of 10 kW with a 5 K drop circulates 1.72 m³/h, 28.7 L/min. Underfloor heating of 8 kW at 5 K needs 1.38 m³/h, 22.9 L/min, and radiators of 20 kW at 20 K need only 0.86 m³/h, 14.3 L/min.
Air changes per hour
Ventilation of rooms is specified in air changes per hour. A room of 50 m³ at 6 changes needs 300 m³/h, 5,000 L/min or 83 L/s. A cleanroom at 60 changes needs 3,000 m³/h, 50,000 L/min, in the same room, which is why cleanrooms are so expensive to run.
Swimming pool and spa plant
A pool pump of 12 m³/h moves 200 L/min. A filter loaded at 30 m/h with an area of 0.4 m² passes 12 m³/h. The pool volume of 48 m³ turns over in 4 hours. Pool plant is often specified in m³/h, while the pump nameplate may show L/min or gal/min.
Gas meters in detail
A residential meter G4 covers 0.04 to 6 m³/h, 0.67 to 100 L/min, and a G6 covers 0.06 to 10 m³/h, 1 to 167 L/min. A commercial G25 reaches 40 m³/h, 667 L/min. The minimum flow limits accuracy, so a pilot flame of 0.02 m³/h may not register on the dial.
Gas pipes
A gas pipe of 22 mm carries 5 to 6 m³/h over a few metres at a modest pressure drop, which is 83 to 100 L/min. A 15 mm pipe carries about 2 m³/h, 33 L/min. The size is chosen from the sum of the appliance flows, each found by dividing its kW by the heating value per m³.
Compressed air for a plant
A plant that needs 300 m³/h, 5,000 L/min, of free air at 7 bar needs a compressor of roughly 33 kW. The figure is the volume of air at atmospheric pressure, which is what the machine sucks in. The same quantity compressed to 7 bar occupies only one eighth of the volume.
Commissioning with an anemometer
On site, air flows are measured with a vane anemometer and a hood. A reading of 8.4 L/s from a bathroom grille equals 30 m³/h and 504 L/min, below the 54 m³/h required. A “convert m³/h to L/min” calculation on the readings turns the instrument display into the schedule units.
A worked example
You are checking a mechanical ventilation system for a flat. The schedule says 90 m³/h for the kitchen and 54 for the bathroom. The anemometer reads 1,400 L/min on the kitchen terminal and 700 L/min on the bathroom. Those are 84 and 42 m³/h, so both are below design by 7 and 22 per cent.
The mental shortcut
To convert m³/h to L/min without a calculator, divide by 6 and tack on two zeros. For 15 m³/h: 15 ÷ 6 = 2.5, giving 250 L/min. The method is exact, because 1,000 ÷ 60 is the same as 100 ÷ 6.
Spreadsheet formulas
Put the m³/h in column A, then =A2*1000/60 in column B gives L/min. The reverse is =B2*0.06. A helper column of =A2*1000/3600 returns litres per second for a cross-check.
Rounding in design documents
Airflows are specified to the nearest 5 or 10 m³/h and measured with an accuracy of about 10 per cent. 54 m³/h is 900 L/min, but 54.0 m³/h is no more precise. Round the result to the same number of significant figures as the input.
Landmarks to memorise
1 m³/h is 16.7 L/min. 3 m³/h is 50 L/min. 6 m³/h is 100 L/min. 30 m³/h is 500 L/min. 60 m³/h is 1,000 L/min. 600 m³/h is 10,000 L/min. With these landmarks nearly every mental convert m³/h to L/min is possible.
Duct sizing
A duct of 200 mm diameter at 3 m/s moves 339 m³/h, 5,655 L/min, and the same duct at 5 m/s moves 565 m³/h but makes more noise. Doubling the diameter quadruples the flow at a given speed. Designers choose a velocity first and read the duct size from the flow.
Reference ladder
0.9 m³/h: 15 L/min. 3.3 m³/h: 55 L/min. 15 m³/h: 250 L/min. 27 m³/h: 450 L/min. 84 m³/h: 1,400 L/min. 150 m³/h: 2,500 L/min. With a list of this kind any result can be checked quickly.
Checking by reversing
Test a “convert m³/h to L/min” calculation answer by multiplying it by 0.06: 450 L/min gives 27.0 m³/h, so the 27 you started from came through intact. A second sign of a good result is that the L/min number is about seventeen times the m³/h one.
Link to litres per second and cubic feet per minute
In one cubic metre per hour there are 16.67 L/min, 0.2778 L/s and 0.5886 CFM. For a 600 m³/h fan that makes 10,000 L/min, 167 L/s and 353 CFM. The units differ and the flow does not, so a “convert m³/h to L/min” calculation only relabels it.
Two routes to one answer
Go straight to L/min with 16.67, or travel via litres an hour: m³/h × 1,000 ÷ 60. A further path uses litres per second, m³/h × 0.2778 × 60. If the answers drift apart, a digit slipped somewhere.
Kitchen and laundry extract
A tumble dryer vented outdoors needs an airflow of 100 to 150 m³/h, 1,670 to 2,500 L/min, through its duct. If the duct is long and kinked, the flow drops by a third and the drying time rises. The same applies to a cooker hood that is duct-connected rather than recirculating.
Boiler flues and combustion air
A gas boiler of 24 kW burning 2.3 m³/h of gas needs about 24 m³/h of combustion air, which is 400 L/min, and produces around 26 m³/h of flue gas at an excess air level that depends on the burner. The flue size follows from the gas flow and the velocity limit, so a “convert m³/h to L/min” calculation is routine in boiler rooms.
Humidifiers and dehumidifiers
A household dehumidifier with a fan of 100 m³/h, 1,670 L/min, takes 0.7 litres of water an hour out of air at 25 °C and 70 per cent humidity. A larger unit of 300 m³/h handles a cellar of 100 m³ in about three air changes an hour, and runs on a trickle drain of well under 1 L/min.
Fan power
Specific fan power is the electrical power per unit of flow. At 1.5 kW per m³/s, a fan moving 1,000 m³/h, 16,667 L/min, 0.278 m³/s, draws 0.42 kW. A well-chosen fan with an efficient motor may achieve 0.8 kW per m³/s, nearly halving that.
Data-centre cooling
A rack that dissipates 10 kW needs about 2,490 m³/h, 41,500 L/min, of air for a 12 K rise. So each kilowatt needs roughly 250 m³/h. Racks of 30 kW can hardly be cooled by air alone at that rise, which is why liquid cooling is being adopted. A “convert m³/h to L/min” calculation gives the flow for a sensor in L/min.
Human breathing
A resting adult breathes about 7.5 L/min, which is 0.45 m³/h. During exercise the figure rises to 100 L/min, 6 m³/h. That is why rooms for exercise need more fresh air: ten athletes working hard breathe 1,000 L/min, 60 m³/h, and breathe out most of the carbon dioxide.
Heat recovery units
A domestic heat-recovery ventilation unit moves 150 to 400 m³/h, 2,500 to 6,670 L/min. At 300 m³/h, 5,000 L/min, and 85 per cent recovery with a 20 K temperature difference, it saves 1.7 kW of heating. The rated flow applies at a specified pressure that depends on the ductwork.
Cooling towers and condensers
A cooling tower circulates about 3 US gpm per ton of refrigeration, which is 0.68 m³/h, 11.4 L/min per 3.5 kW of cooling. A chiller of 100 kW needs a condenser water flow of 19.5 m³/h, 326 L/min, for a rise of 5.5 K when its heat rejection is 125 kW.
Fan coil units
A fan coil unit of 2 kW cooling with a 5 K water rise needs 0.34 m³/h, 5.7 L/min, of chilled water. A room of four such units takes 1.4 m³/h, 23 L/min. Small flows such as these are why fan coils are connected with 15 mm pipes.
Circulating pumps
A circulator of 6 m³/h, 100 L/min, at 4 m head has hydraulic power of 65 W. Modern high-efficiency circulators draw 20 to 60 W for such duties, against 100 W for older models. Pump curves are drawn in m³/h and metres, and the operating point lies where the pump curve meets the pipe curve.
More values for convert m³/h to L/min
A longer list of conversions
If the value you need is not in the first list, these further conversions may be close enough to read off directly:
- 0.1 m³/h = 1.66667 L/min
- 0.5 m³/h = 8.33333 L/min
- 3 m³/h = 50 L/min
- 4 m³/h = 66.6667 L/min
- 7 m³/h = 116.667 L/min
- 15 m³/h = 250 L/min
- 20 m³/h = 333.333 L/min
- 75 m³/h = 1,250 L/min
- 200 m³/h = 3,333.33 L/min
- 500 m³/h = 8,333.33 L/min
- 2,000 m³/h = 33,333.3 L/min
- 10,000 m³/h = 166,667 L/min
Common slips with a “convert m³/h to L/min” calculation
The inverse factor
Moving from m³/h to L/min must enlarge the figure. A result of 0.36 for 6 m³/h shows the wrong factor was used.
Three time units
10 L/s equals 36 m³/h and 600 L/min. Ventilation rules often use L/s, fan plates m³/h and instruments L/min, so read the unit twice before multiplying.
Standard against actual volume
Gas and compressed air are often quoted at standard conditions. 300 m³/h of free air is not 300 m³/h in a pipe at 7 bar. Use the same reference conditions on both sides of the conversion.
Short answers
How do I convert m³/h to L/min?
Take the cubic metres per hour times 16.67.
What is 6 m³/h in L/min?
It is 100 L/min.
What is 600 m³/h in L/min?
It is 10,000 L/min.
What is 100 L/min in m³/h?
It is 6 m³/h.
Is my number sent anywhere?
No, everything is computed in the browser.
More pages and a wrap-up
Other flow conversions are listed in Convert gal/min to L/min, Convert L/min to gal/min, Convert km to mi, Convert mi to km, Convert °C to °F, Convert °F to °C, Convert L to fl oz, Convert bar to psi, Convert nm to m. Going the other way is covered by Convert L/min to m³/h.
To sum up, a “convert m³/h to L/min” calculation needs one multiplication by 16.67 and a unit beside the answer. The figure is worked out on your own device, without registration or upload.