One foot of water is exactly 0.029890669 bar, so converting feet of water to bar is a single multiplication. Enter any figure and the result appears as you type — the arithmetic runs in your browser, so nothing is sent anywhere.
Almost exactly atmospheric pressure; standard in European industry and diving. Pump head expressed as a column of water — the way pump curves are drawn.
Gauge versus absolute. A tyre gauge reading 32 psi means 32 psi above atmospheric, which is about 46.7 psi absolute. Converting the number is straightforward; remembering which zero it was measured from is where the mistakes happen. N/mm² and MPa are the same size, so a drawing quoting either is quoting the same stress. Below the calculator there is a step table for the values people look up most, and a second table putting real pressure figures into bar so the number you get has something to be compared against.
The formula
feet of water- The amount you are converting, in feet of water
0.029890669- The exact number of bar in one foot of water
bar- The converted result
How it works, step by step
- Enter the value in feet of water.
- It is multiplied by 0.029890669, the exact factor between the two units.
- The answer is shown in bar, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
A car tyre: 73.8 ftH₂O in bar
At 73.8 ftH₂O (a car tyre), the same quantity in bar is 73.8 × 0.0298907 = 2.20593 bar. One foot of water is 0.0298907 bar, so the numbers shrink as expected.
Sea-level air: 33.9 ftH₂O in bar
At 33.9 ftH₂O (sea-level air), the same quantity in bar is 33.9 × 0.0298907 = 1.01329 bar. One foot of water is 0.0298907 bar, so the numbers shrink as expected.
How to read your score
Frequently asked questions
How many bar are in one foot of water?
Exactly 0.029890669. 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 feet of water to bar?
bar = feet of water × 0.029890669. Reversed, feet of water = bar ÷ 0.029890669, which is the same as multiplying by 33.4552565551.
Which is the bigger unit, the foot of water or the bar?
The bar. One foot of water is only 0.0298907 of a bar, so it takes 33.4553 feet of water to make one bar.
What does this quantity actually measure?
Both units measure pressure. 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 foot of water?
Pump head expressed as a column of water — the way pump curves are drawn.
What is a bar?
Almost exactly atmospheric pressure; standard in European industry and diving.
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 ftH₂O to bar in my head?
Plenty of people do this in their head: divide by 33 instead of using the exact factor 0.029890669. At 100 that shortcut gives 3.030303 bar, off by 0.04124 bar or about 1.38%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Feet Of Water to bar reference tables
| Feet Of Water | Bar |
|---|---|
| 0.5 ftH₂O | 0.0149453 bar |
| 1 ftH₂O | 0.0298907 bar |
| 2 ftH₂O | 0.0597813 bar |
| 3 ftH₂O | 0.089672 bar |
| 5 ftH₂O | 0.149453 bar |
| 10 ftH₂O | 0.298907 bar |
| 20 ftH₂O | 0.597813 bar |
| 25 ftH₂O | 0.747267 bar |
| 50 ftH₂O | 1.49453 bar |
| 75 ftH₂O | 2.2418 bar |
| 100 ftH₂O | 2.98907 bar |
| 250 ftH₂O | 7.47267 bar |
| 500 ftH₂O | 14.9453 bar |
| 1000 ftH₂O | 29.8907 bar |
| 5000 ftH₂O | 149.453 bar |
Exact factor: 1 foot of water = 0.029890669 bar.
| Quantity | ftH₂O | bar |
|---|---|---|
| Sea-level air | 33.9 ftH₂O | 1.013 bar |
| A car tyre | 73.81 ftH₂O | 2.206 bar |
| Blood pressure, systolic | 5.352 ftH₂O | 0.16 bar |
| A bicycle tyre | 207.6 ftH₂O | 6.205 bar |
| A domestic water main | 133.8 ftH₂O | 4 bar |
| A steam boiler | 334.6 ftH₂O | 10 bar |
Published reference values, converted with the same factor this page uses.