To convert US gallons per day to cubic meters per hour, multiply by 0.0001577254585. 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.
The rating unit for reverse-osmosis membranes and water demand. 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
US gallons per day- The amount you are converting, in US gallons per day
0.000157725458473- The exact number of cubic meters per hour in one US gallon per day
cubic meters per hour- The converted result
How it works, step by step
- Enter the value in US gallons per day.
- It is multiplied by 0.000157725458473, 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: 1.37e+06 GPD in cubic meters per hour
At 1.37e+06 GPD (a fire hydrant), the same quantity in cubic meters per hour is 1.37e+06 × 0.000157725 = 216.084 m³/h. One US gallon per day is 0.000157725 cubic meters per hour, so the numbers shrink as expected.
A bathroom tap: 2280 GPD in cubic meters per hour
Take a bathroom tap, roughly 2280 GPD. The conversion is a single multiplication — 2280 × 0.000157725 — giving 0.359614 m³/h. Because the relationship is proportional, doubling the input doubles the answer to 0.719228 m³/h.
How to read your score
Frequently asked questions
How many cubic meters per hour are in one US gallon per day?
Exactly 0.000157725458473. 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 US gallons per day to cubic meters per hour?
cubic meters per hour = US gallons per day × 0.000157725458473. Reversed, US gallons per day = cubic meters per hour ÷ 0.000157725458473, which is the same as multiplying by 6340.13056409.
Which is the bigger unit, the US gallon per day or the cubic meter per hour?
The cubic meter per hour. One US gallon per day is only 0.000157725 of a cubic meter per hour, so it takes 6340.13 US gallons per day to make one cubic meter 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 US gallon per day?
The rating unit for reverse-osmosis membranes and water demand.
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 GPD to m³/h in my head?
Plenty of people do this in their head: divide by 6300 instead of using the exact factor 0.0001577254585. At 100 that shortcut gives 0.015873016 cubic meters per hour, off by 0.0001005 cubic meters per hour or about 0.64%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Us Gallons Per Day to cubic meters per hour reference tables
| Us Gallons Per Day | Cubic Meters Per Hour |
|---|---|
| 0.5 GPD | 7.88627e-05 m³/h |
| 1 GPD | 0.000157725 m³/h |
| 2 GPD | 0.000315451 m³/h |
| 3 GPD | 0.000473176 m³/h |
| 5 GPD | 0.000788627 m³/h |
| 10 GPD | 0.00157725 m³/h |
| 20 GPD | 0.00315451 m³/h |
| 25 GPD | 0.00394314 m³/h |
| 50 GPD | 0.00788627 m³/h |
| 75 GPD | 0.0118294 m³/h |
| 100 GPD | 0.0157725 m³/h |
| 250 GPD | 0.0394314 m³/h |
| 500 GPD | 0.0788627 m³/h |
| 1000 GPD | 0.157725 m³/h |
| 5000 GPD | 0.788627 m³/h |
Exact factor: 1 US gallon per day = 0.000157725458473 cubic meters per hour.
| Quantity | GPD | m³/h |
|---|---|---|
| A dripping tap | 2.282 GPD | 0.00036 m³/h |
| A bathroom tap | 2282 GPD | 0.36 m³/h |
| A shower head | 3652 GPD | 0.576 m³/h |
| A garden hose | 6847 GPD | 1.08 m³/h |
| A fire hydrant | 1.369e+06 GPD | 216 m³/h |
| The Thames at London | 1.484e+09 GPD | 2.34e+05 m³/h |
Published reference values, converted with the same factor this page uses.