cubic meters per hour to US gallons per minute

An international irrigation design says 10 m³/h; the American pump dealer asks how many GPM. The answer is 44.03, through the exact factor 4.4028675393 — the number of US gallons per minute in one cubic meter per hour, built from the liter, the 231 in³ gallon, and the hour. Every imported pump, every chiller, and every irrigation controller crosses this line.

1 cubic meter per hour = 4.402868 US gallons per minute, and 1 US gallon per minute = 0.22712470704 cubic meters per hour. Every value on this page scales by the same factor: multiply m³/h by 4.402868. Worked: 10 m³/h = 44.02868 US gal/min; 100 m³/h = 440.2868 US gal/min.

By EnginStack Editorial Team | Reviewed against NIST, BIPM and primary-source documentation About →
cubic meters per hour
44.02867539 US gallons per minute
10 cubic meters per hour = 44.02867539 US gallons per minute 10 US gallons per minute = 2.27124707 cubic meters per hour

Authority: NIST SP 811 (SI usage guide) and the 1959 International Yard and Pound Agreement. The coefficient above is a defined value — it does not come from measurement and carries no uncertainty.

cubic meters per hour to US gallons per minute

One m³/h is 1,000 L/min ÷ 60 = 16.6666666667 L/min, and one GPM is 3.785411784 L/min, so one m³/h is 16.6666666667 / 3.785411784 = 4.4028675393 GPM. The factor is exact — a ratio of three definitions (the meter, the gallon, the hour) with no measured constant anywhere. Agriculture, HVAC, and water treatment flip between m³/h and GPM constantly, and the exact factor is the only safe way to do it.

US gallons per minute = cubic meters per hour × 4.4028675393
1 m³/h = 4.4028675393 GPM — 16.6666666667 ÷ 3.785411784
The factor is exact from three definitions.

Worked Examples

Example 1: Convert a 5 m³/h irrigation supply

5 × 4.4028675393 = 22.01 GPM

Example 2: Convert a 30 m³/h process line

30 × 4.4028675393 = 132.09 GPM

Example 3: Convert a 500 m³/h municipal feed

500 × 4.4028675393 = 2,201.43 GPM

Common cubic meters per hour to US gallons per minute Conversions

cubic meters per hourUS gallons per minuteContext
1 m³/h4.40 GPMThe definitional anchor.
10 m³/h44.03 GPMA small irrigation pump.
50 m³/h220.1 GPMA center-pivot irrigation supply.
100 m³/h440.3 GPMA chiller water loop.
1,000 m³/h4,402.9 GPMA municipal treatment feed.

Engineering Context

This is the reciprocal of the GPM to m³/h page. Its anchors are the cubic meters to liters and gallons to liters volume converters, plus the time family's hour. The flow rate hub collects all ten flow converters, and irrigation water demand also connects to the area pages when calculating application depth.

This direction is the one you need when a plant is designed to SI standards and the rotating equipment is bought from a North American supplier, or the reverse. Water utility and process design packages give a flow rate in cubic meters per hour because the rest of the calculation is in liters, meters and bars; the pump datasheet gives gallons per minute because the manufacturer publishes one document for the whole world. The numbers on the two documents are not in conflict, but they are also not comparable until one of them has been converted, and a difference of a few percent at the nominal duty point is usually a rounding difference rather than a real mismatch.

More: GPM to m³/h · m³/h to L/min · m³ to gal · Flow Rate Guide · Flow Rate Hub

Related Unit Converters

US gallons per minute to cubic meters per hour cubic meters per hour to liters per minute cubic meters to gallons Flow Rate Conversion Guide Flow Rate Converters

Frequently Asked Questions

How many GPM is 1 m³/h?

Exactly 4.4028675393. One m³/h is 16.6666666667 L/min, and one GPM is 3.785411784 L/min, so the ratio is exact.

Why does irrigation mix m³/h and GPM?

Because equipment comes from both unit worlds: European controllers and drip systems are designed in m³/h, while US pumps and wells are rated in GPM. The same irrigation block gets sized in both units depending on the vendor.

Is the 4.4 factor safe to round?

4.4 is within 0.07% — fine for rough sizing. For pump selection, use the full 4.4028675393, since a small flow error compounds over irrigation season water totals.