This page converts acre-feet per day into imperial gallons per minute using the factor 188.4222726, 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. Irrigation and reservoir release rates in the western United States.
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. Below the calculator there is a step table for the values people look up most, and a second table putting real volumetric flow figures into imperial gallons per minute so the number you get has something to be compared against.
The formula
acre-feet per day- The amount you are converting, in acre-feet per day
188.42227263- The exact number of imperial gallons per minute in one acre-foot per day
imperial gallons per minute- The converted result
How it works, step by step
- Enter the value in acre-feet per day.
- It is multiplied by 188.42227263, 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 garden hose: 0.021 ac ft/d in imperial gallons per minute
At 0.021 ac ft/d (a garden hose), the same quantity in imperial gallons per minute is 0.021 × 188.422 = 3.95687 gpm. One acre-foot per day is 188.422 imperial gallons per minute, so the numbers grow as expected.
A bathroom tap: 0.007 ac ft/d in imperial gallons per minute
Take a bathroom tap, roughly 0.007 ac ft/d. The conversion is a single multiplication — 0.007 × 188.422 — giving 1.31896 gpm. Because the relationship is proportional, doubling the input doubles the answer to 2.63791 gpm.
How to read your score
Frequently asked questions
How many imperial gallons per minute are in one acre-foot per day?
Exactly 188.42227263. 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 acre-feet per day to imperial gallons per minute?
imperial gallons per minute = acre-feet per day × 188.42227263. Reversed, acre-feet per day = imperial gallons per minute ÷ 188.42227263, which is the same as multiplying by 0.00530722820632.
Which is the bigger unit, the acre-foot per day or the imperial gallon per minute?
The acre-foot per day. One acre-foot per day equals 188.422 imperial gallons 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 acre-foot per day?
Irrigation and reservoir release rates in the western United States.
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 ac ft/d to gpm in my head?
Plenty of people do this in their head: multiply by 190 instead of using the exact factor 188.4222726. At 100 that shortcut gives 19,000 imperial gallons per minute, off by 157.8 imperial gallons per minute or about 0.84%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Acre-Feet Per Day to imperial gallons per minute reference tables
| Acre-Feet Per Day | Imperial Gallons Per Minute |
|---|---|
| 0.5 ac ft/d | 94.2111 gpm |
| 1 ac ft/d | 188.422 gpm |
| 2 ac ft/d | 376.845 gpm |
| 3 ac ft/d | 565.267 gpm |
| 5 ac ft/d | 942.111 gpm |
| 10 ac ft/d | 1884.22 gpm |
| 20 ac ft/d | 3768.45 gpm |
| 25 ac ft/d | 4710.56 gpm |
| 50 ac ft/d | 9421.11 gpm |
| 75 ac ft/d | 14,131.7 gpm |
| 100 ac ft/d | 18,842.2 gpm |
| 250 ac ft/d | 47,105.6 gpm |
| 500 ac ft/d | 94,211.1 gpm |
| 1000 ac ft/d | 188,422 gpm |
| 5000 ac ft/d | 942,111 gpm |
Exact factor: 1 acre-foot per day = 188.42227263 imperial gallons per minute.
| Quantity | ac ft/d | gpm |
|---|---|---|
| A dripping tap | 7.005e-06 ac ft/d | 0.00132 gpm |
| A bathroom tap | 0.007005 ac ft/d | 1.32 gpm |
| A shower head | 0.01121 ac ft/d | 2.112 gpm |
| A garden hose | 0.02101 ac ft/d | 3.959 gpm |
| A fire hydrant | 4.203 ac ft/d | 791.9 gpm |
| The Thames at London | 4553 ac ft/d | 8.579e+05 gpm |
Published reference values, converted with the same factor this page uses.