This page converts acre-feet per day into cubic feet per second using the factor 0.5041666667, and shows the reverse figure alongside it. Both units measure volumetric flow, which is why one number does the whole job.
The cusec — how American river gauges and water rights report flow. 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. The tables underneath give both a plain step-by-step lookup and a list of real quantities expressed in cubic feet per second, so you can sanity-check whether your answer is a plausible size.
The formula
acre-feet per day- The amount you are converting, in acre-feet per day
0.50416666665- The exact number of cubic feet per second in one acre-foot per day
cubic feet per second- The converted result
How it works, step by step
- Enter the value in acre-feet per day.
- It is multiplied by 0.50416666665, the exact factor between the two units.
- The answer is shown in cubic feet per second, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
A shower head: 0.0112 ac ft/d in cubic feet per second
At 0.0112 ac ft/d (a shower head), the same quantity in cubic feet per second is 0.0112 × 0.504167 = 0.00564667 cfs. One acre-foot per day is 0.504167 cubic feet per second, so the numbers shrink as expected.
A bathroom tap: 0.007 ac ft/d in cubic feet per second
A bathroom tap comes to about 0.007 ac ft/d. Multiplying by the factor: 0.007 × 0.504167 = 0.00352917 cfs. Dividing the answer back by 0.504167 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
How to read your score
Frequently asked questions
How many cubic feet per second are in one acre-foot per day?
Exactly 0.50416666665. 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 cubic feet per second?
cubic feet per second = acre-feet per day × 0.50416666665. Reversed, acre-feet per day = cubic feet per second ÷ 0.50416666665, which is the same as multiplying by 1.98347107444.
Which is the bigger unit, the acre-foot per day or the cubic foot per second?
The cubic foot per second. One acre-foot per day is only 0.504167 of a cubic foot per second, so it takes 1.98347 acre-feet per day to make one cubic foot per second.
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 cubic foot per second?
The cusec — how American river gauges and water rights report flow.
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 cfs in my head?
Plenty of people do this in their head: divide by 2 instead of using the exact factor 0.5041666667. At 100 that shortcut gives 50 cubic feet per second, off by 0.4167 cubic feet per second or about 0.83%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Acre-Feet Per Day to cubic feet per second reference tables
| Acre-Feet Per Day | Cubic Feet Per Second |
|---|---|
| 0.5 ac ft/d | 0.252083 cfs |
| 1 ac ft/d | 0.504167 cfs |
| 2 ac ft/d | 1.00833 cfs |
| 3 ac ft/d | 1.5125 cfs |
| 5 ac ft/d | 2.52083 cfs |
| 10 ac ft/d | 5.04167 cfs |
| 20 ac ft/d | 10.0833 cfs |
| 25 ac ft/d | 12.6042 cfs |
| 50 ac ft/d | 25.2083 cfs |
| 75 ac ft/d | 37.8125 cfs |
| 100 ac ft/d | 50.4167 cfs |
| 250 ac ft/d | 126.042 cfs |
| 500 ac ft/d | 252.083 cfs |
| 1000 ac ft/d | 504.167 cfs |
| 5000 ac ft/d | 2520.83 cfs |
Exact factor: 1 acre-foot per day = 0.50416666665 cubic feet per second.
| Quantity | ac ft/d | cfs |
|---|---|---|
| A dripping tap | 7.005e-06 ac ft/d | 3.531e-06 cfs |
| A bathroom tap | 0.007005 ac ft/d | 0.003531 cfs |
| A shower head | 0.01121 ac ft/d | 0.00565 cfs |
| A garden hose | 0.02101 ac ft/d | 0.01059 cfs |
| A fire hydrant | 4.203 ac ft/d | 2.119 cfs |
| The Thames at London | 4553 ac ft/d | 2295 cfs |
Published reference values, converted with the same factor this page uses.