This page converts cubic feet per hour into imperial gallons per minute using the factor 0.1038139243, and shows the reverse figure alongside it. Both units measure volumetric flow, which is why one number does the whole job.
The British pump unit, about 20% more volume per minute than the US gallon version. Gas appliance and small-flow rating in the US.
Standard versus actual volume. Gas flow in CFM depends on pressure and temperature, which is why compressor ratings say SCFM and specify the reference conditions. Converting the number is exact; comparing two ratings measured at different conditions is not. The tables underneath give both a plain step-by-step lookup and a list of real quantities expressed in imperial gallons per minute, so you can sanity-check whether your answer is a plausible size.
The formula
cubic feet per hour- The amount you are converting, in cubic feet per hour
0.103813924317- The exact number of imperial gallons per minute in one cubic foot per hour
imperial gallons per minute- The converted result
How it works, step by step
- Enter the value in cubic feet per hour.
- It is multiplied by 0.103813924317, the exact factor between the two units.
- The answer is shown in imperial gallons per minute, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
A shower head: 20.3 CFH in imperial gallons per minute
A shower head comes to about 20.3 CFH. Multiplying by the factor: 20.3 × 0.103814 = 2.10742 gpm. Dividing the answer back by 0.103814 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
A dripping tap: 0.0127 CFH in imperial gallons per minute
Take a dripping tap, roughly 0.0127 CFH. The conversion is a single multiplication — 0.0127 × 0.103814 — giving 0.00131844 gpm. Because the relationship is proportional, doubling the input doubles the answer to 0.00263687 gpm.
How to read your score
Frequently asked questions
How many imperial gallons per minute are in one cubic foot per hour?
Exactly 0.103813924317. Every figure on this page is that one number multiplied by your input, so the only rounding is at the display step.
What is the formula to convert cubic feet per hour to imperial gallons per minute?
imperial gallons per minute = cubic feet per hour × 0.103813924317. Reversed, cubic feet per hour = imperial gallons per minute ÷ 0.103813924317, which is the same as multiplying by 9.63261919415.
Which is the bigger unit, the cubic foot per hour or the imperial gallon per minute?
The imperial gallon per minute. One cubic foot per hour is only 0.103814 of a imperial gallon per minute, so it takes 9.63262 cubic feet per hour to make one imperial gallon per minute.
What does this quantity actually measure?
Both units measure volumetric flow. That is why a single factor is enough: there is no temperature offset and no material property involved, unlike conversions that cross between different quantities.
What is a cubic foot per hour?
Gas appliance and small-flow rating in the US.
What is a imperial gallon per minute?
The British pump unit, about 20% more volume per minute than the US gallon version.
Why does my answer differ from another converter?
Almost always because the other tool rounded the factor before multiplying. This page keeps full double precision through the calculation and rounds only for display, and it prints the factor it used so you can see where any difference came from.
Is there a quick way to do CFH to gpm in my head?
Plenty of people do this in their head: divide by 10 instead of using the exact factor 0.1038139243. At 100 that shortcut gives 10 imperial gallons per minute, off by 0.3814 imperial gallons per minute or about 3.67%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Cubic Feet Per Hour to imperial gallons per minute reference tables
| Cubic Feet Per Hour | Imperial Gallons Per Minute |
|---|---|
| 0.5 CFH | 0.051907 gpm |
| 1 CFH | 0.103814 gpm |
| 2 CFH | 0.207628 gpm |
| 3 CFH | 0.311442 gpm |
| 5 CFH | 0.51907 gpm |
| 10 CFH | 1.03814 gpm |
| 20 CFH | 2.07628 gpm |
| 25 CFH | 2.59535 gpm |
| 50 CFH | 5.1907 gpm |
| 75 CFH | 7.78604 gpm |
| 100 CFH | 10.3814 gpm |
| 250 CFH | 25.9535 gpm |
| 500 CFH | 51.907 gpm |
| 1000 CFH | 103.814 gpm |
| 5000 CFH | 519.07 gpm |
Exact factor: 1 cubic foot per hour = 0.103813924317 imperial gallons per minute.
| Quantity | CFH | gpm |
|---|---|---|
| A dripping tap | 0.01271 CFH | 0.00132 gpm |
| A bathroom tap | 12.71 CFH | 1.32 gpm |
| A shower head | 20.34 CFH | 2.112 gpm |
| A garden hose | 38.14 CFH | 3.959 gpm |
| A fire hydrant | 7628 CFH | 791.9 gpm |
| The Thames at London | 8.264e+06 CFH | 8.579e+05 gpm |
Published reference values, converted with the same factor this page uses.