To convert acre-feet per day to cubic meters per hour, multiply by 51.39507656. That factor is the whole relationship: both units measure volumetric flow, so the conversion is a proportion with no offset and no substance-specific constant.
Irrigation and reservoir release rates in the western United States. The standard rating unit for pumps and ventilation in metric markets.
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 cubic meters per hour 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
51.3950765628- The exact number of cubic meters per hour in one acre-foot per day
cubic meters per hour- The converted result
How it works, step by step
- Enter the value in acre-feet per day.
- It is multiplied by 51.3950765628, the exact factor between the two units.
- The answer is shown in cubic meters per hour, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
A fire hydrant: 4.2 ac ft/d in cubic meters per hour
A fire hydrant comes to about 4.2 ac ft/d. Multiplying by the factor: 4.2 × 51.3951 = 215.859 m³/h. Dividing the answer back by 51.3951 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
A garden hose: 0.021 ac ft/d in cubic meters per hour
A garden hose comes to about 0.021 ac ft/d. Multiplying by the factor: 0.021 × 51.3951 = 1.0793 m³/h. Dividing the answer back by 51.3951 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 meters per hour are in one acre-foot per day?
Exactly 51.3950765628. 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 meters per hour?
cubic meters per hour = acre-feet per day × 51.3950765628. Reversed, acre-feet per day = cubic meters per hour ÷ 51.3950765628, which is the same as multiplying by 0.0194571166516.
Which is the bigger unit, the acre-foot per day or the cubic meter per hour?
The acre-foot per day. One acre-foot per day equals 51.3951 cubic meters per hour.
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 meter per hour?
The standard rating unit for pumps and ventilation in metric markets.
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 m³/h in my head?
Plenty of people do this in their head: multiply by 50 instead of using the exact factor 51.39507656. At 100 that shortcut gives 5000 cubic meters per hour, off by 139.5 cubic meters per hour or about 2.71%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Acre-Feet Per Day to cubic meters per hour reference tables
| Acre-Feet Per Day | Cubic Meters Per Hour |
|---|---|
| 0.5 ac ft/d | 25.6975 m³/h |
| 1 ac ft/d | 51.3951 m³/h |
| 2 ac ft/d | 102.79 m³/h |
| 3 ac ft/d | 154.185 m³/h |
| 5 ac ft/d | 256.975 m³/h |
| 10 ac ft/d | 513.951 m³/h |
| 20 ac ft/d | 1027.9 m³/h |
| 25 ac ft/d | 1284.88 m³/h |
| 50 ac ft/d | 2569.75 m³/h |
| 75 ac ft/d | 3854.63 m³/h |
| 100 ac ft/d | 5139.51 m³/h |
| 250 ac ft/d | 12,848.8 m³/h |
| 500 ac ft/d | 25,697.5 m³/h |
| 1000 ac ft/d | 51,395.1 m³/h |
| 5000 ac ft/d | 256,975 m³/h |
Exact factor: 1 acre-foot per day = 51.3950765628 cubic meters per hour.
| Quantity | ac ft/d | m³/h |
|---|---|---|
| A dripping tap | 7.005e-06 ac ft/d | 0.00036 m³/h |
| A bathroom tap | 0.007005 ac ft/d | 0.36 m³/h |
| A shower head | 0.01121 ac ft/d | 0.576 m³/h |
| A garden hose | 0.02101 ac ft/d | 1.08 m³/h |
| A fire hydrant | 4.203 ac ft/d | 216 m³/h |
| The Thames at London | 4553 ac ft/d | 2.34e+05 m³/h |
Published reference values, converted with the same factor this page uses.