Flow-rate converter
Conversion history
| Time | Input | Result | Standard |
|---|
Formula used
Imperial gallons: m³/h = GPM × 0.2727654
Reverse conversion: GPM = m³/h ÷ selected factor
US and Imperial gallons have different liquid volumes. Select the correct standard before calculating any result. This prevents avoidable errors in engineering flow comparisons.
How to use this calculator
Select a direction and the correct gallon standard. Enter one value or paste several batch values. Choose precision, calculate, then review every converted result carefully.
- Choose single or batch calculation mode.
- Select GPM to m³/h or reverse conversion.
- Choose US liquid or Imperial gallons.
- Enter values and set formatting preferences.
- Calculate, copy, export, share, or print results.
Example conversion table
| US GPM | Cubic meters per hour | Imperial GPM equivalent |
|---|---|---|
| 1 | 0.227125 m³/h | 0.832674 Imperial GPM |
| 5 | 1.135624 m³/h | 4.163371 Imperial GPM |
| 10 | 2.271247 m³/h | 8.326742 Imperial GPM |
| 25 | 5.678118 m³/h | 20.816855 Imperial GPM |
| 50 | 11.356235 m³/h | 41.633709 Imperial GPM |
| 100 | 22.712471 m³/h | 83.267418 Imperial GPM |
These examples use exact published gallon definitions. Displayed values are rounded to six decimal places. Increase precision when small differences affect important decisions.
US and Imperial gallon comparison
| Standard | Liters per gallon | m³/h per GPM |
|---|---|---|
| US liquid gallon | 3.785411784 | 0.22712470704 |
| Imperial gallon | 4.54609 | 0.2727654 |
Imperial gallons contain more liquid than US gallons. Identical GPM readings therefore represent different hourly volumes. Always verify equipment labels before selecting your standard.
Frequently asked questions
What does GPM mean?
GPM means gallons flowing during one minute. It describes pumps, pipes, and water systems. The gallon standard determines the actual liquid volume.
What does m³/h mean?
It means cubic meters flowing during one hour. The unit is common in metric engineering. One cubic meter contains exactly one thousand liters.
Why are two gallon standards available?
US and Imperial gallons have different definitions. Their conversion factors therefore cannot be interchanged. Selecting incorrectly creates a meaningful measurement error.
How accurate is the conversion?
The calculator uses exact gallon definitions. Final accuracy also depends on input quality. Choose enough decimal places for your application.
Can I convert m³/h back to GPM?
Yes, select the reverse conversion direction. The calculator divides using the selected factor. Results update for US or Imperial gallons.
Can this calculator process many values?
Yes, choose batch calculation mode first. Paste values separated by common delimiters. The tool returns statistics and downloadable CSV data.
Are negative flow values allowed?
Negative values are disabled by default. Enable them for signed reverse-flow measurements. Confirm your instrument uses the same direction convention.
What is scientific notation?
Scientific notation shortens extremely large or small values. It uses powers of ten for readability. Enable it when ordinary decimals become difficult.
Does rounding change the stored result?
Rounding only changes the displayed number. Calculations retain full floating-point precision internally. The unrounded result remains visible after conversion.
What does the PDF button do?
It opens the browser printing dialog. Choose the save-to-PDF destination there. Printed pages hide controls for cleaner documentation.
Can results be used for equipment sizing?
The converter supports preliminary flow comparisons. Equipment sizing needs pressure and system data. Verify critical selections with qualified engineering guidance.
Results support estimation and documentation tasks. They do not replace calibrated flow measurements. Confirm critical values before operational or safety decisions.