This page converts feet of water into megapascals using the factor 0.0029890669, and shows the reverse figure alongside it. Both units measure pressure, which is why one number does the whole job.
Pump head expressed as a column of water — the way pump curves are drawn. Used for material strength and hydraulic systems.
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 megapascals 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
0.0029890669- The exact number of megapascals in one foot of water
megapascals- The converted result
How it works, step by step
- Enter the value in feet of water.
- It is multiplied by 0.0029890669, the exact factor between the two units.
- The answer is shown in megapascals, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
Blood pressure, systolic: 5.35 ftH₂O in megapascals
Blood pressure, systolic comes to about 5.35 ftH₂O. Multiplying by the factor: 5.35 × 0.00298907 = 0.0159915 MPa. Dividing the answer back by 0.00298907 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
A bicycle tyre: 208 ftH₂O in megapascals
Take a bicycle tyre, roughly 208 ftH₂O. The conversion is a single multiplication — 208 × 0.00298907 — giving 0.621726 MPa. Because the relationship is proportional, doubling the input doubles the answer to 1.24345 MPa.
How to read your score
Frequently asked questions
How many megapascals are in one foot of water?
Exactly 0.0029890669. 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 megapascals?
megapascals = feet of water × 0.0029890669. Reversed, feet of water = megapascals ÷ 0.0029890669, which is the same as multiplying by 334.552565551.
Which is the bigger unit, the foot of water or the megapascal?
The megapascal. One foot of water is only 0.00298907 of a megapascal, so it takes 334.553 feet of water to make one megapascal.
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 megapascal?
Used for material strength and hydraulic systems.
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 MPa in my head?
Plenty of people do this in their head: divide by 330 instead of using the exact factor 0.0029890669. At 100 that shortcut gives 0.3030303 megapascals, off by 0.004124 megapascals or about 1.38%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Feet Of Water to megapascals reference tables
| Feet Of Water | Megapascals |
|---|---|
| 0.5 ftH₂O | 0.00149453 MPa |
| 1 ftH₂O | 0.00298907 MPa |
| 2 ftH₂O | 0.00597813 MPa |
| 3 ftH₂O | 0.0089672 MPa |
| 5 ftH₂O | 0.0149453 MPa |
| 10 ftH₂O | 0.0298907 MPa |
| 20 ftH₂O | 0.0597813 MPa |
| 25 ftH₂O | 0.0747267 MPa |
| 50 ftH₂O | 0.149453 MPa |
| 75 ftH₂O | 0.22418 MPa |
| 100 ftH₂O | 0.298907 MPa |
| 250 ftH₂O | 0.747267 MPa |
| 500 ftH₂O | 1.49453 MPa |
| 1000 ftH₂O | 2.98907 MPa |
| 5000 ftH₂O | 14.9453 MPa |
Exact factor: 1 foot of water = 0.0029890669 megapascals.
| Quantity | ftH₂O | MPa |
|---|---|---|
| Sea-level air | 33.9 ftH₂O | 0.1013 MPa |
| A car tyre | 73.81 ftH₂O | 0.2206 MPa |
| Blood pressure, systolic | 5.352 ftH₂O | 0.016 MPa |
| A bicycle tyre | 207.6 ftH₂O | 0.6205 MPa |
| A domestic water main | 133.8 ftH₂O | 0.4 MPa |
| A steam boiler | 334.6 ftH₂O | 1 MPa |
Published reference values, converted with the same factor this page uses.