This page converts centimeters of water into pascals using the factor 98.0665, and shows the reverse figure alongside it. Both units measure pressure, which is why one number does the whole job.
The SI unit: one newton per square metre. The unit ventilator and CPAP pressures are set in.
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. The tables underneath give both a plain step-by-step lookup and a list of real quantities expressed in pascals, so you can sanity-check whether your answer is a plausible size.
The formula
centimeters of water- The amount you are converting, in centimeters of water
98.0665- The exact number of pascals in one centimeter of water
pascals- The converted result
How it works, step by step
- Enter the value in centimeters of water.
- It is multiplied by 98.0665, the exact factor between the two units.
- The answer is shown in pascals, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
A car tyre: 2250 cmH₂O in pascals
A car tyre comes to about 2250 cmH₂O. Multiplying by the factor: 2250 × 98.0665 = 220,650 Pa. Dividing the answer back by 98.0665 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
Blood pressure, systolic: 163 cmH₂O in pascals
Blood pressure, systolic comes to about 163 cmH₂O. Multiplying by the factor: 163 × 98.0665 = 15,984.8 Pa. Dividing the answer back by 98.0665 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 pascals are in one centimeter of water?
Exactly 98.0665. 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 centimeters of water to pascals?
pascals = centimeters of water × 98.0665. Reversed, centimeters of water = pascals ÷ 98.0665, which is the same as multiplying by 0.0101971621298.
Which is the bigger unit, the centimeter of water or the pascal?
The centimeter of water. One centimeter of water equals 98.0665 pascals.
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 centimeter of water?
The unit ventilator and CPAP pressures are set in.
What is a pascal?
The SI unit: one newton per square metre.
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 cmH₂O to Pa in my head?
Plenty of people do this in their head: multiply by 100 instead of using the exact factor 98.0665. At 100 that shortcut gives 10,000 pascals, off by 193.4 pascals or about 1.97%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Centimeters Of Water to pascals reference tables
| Centimeters Of Water | Pascals |
|---|---|
| 0.5 cmH₂O | 49.0333 Pa |
| 1 cmH₂O | 98.0665 Pa |
| 2 cmH₂O | 196.133 Pa |
| 3 cmH₂O | 294.2 Pa |
| 5 cmH₂O | 490.333 Pa |
| 10 cmH₂O | 980.665 Pa |
| 20 cmH₂O | 1961.33 Pa |
| 25 cmH₂O | 2451.66 Pa |
| 50 cmH₂O | 4903.32 Pa |
| 75 cmH₂O | 7354.99 Pa |
| 100 cmH₂O | 9806.65 Pa |
| 250 cmH₂O | 24,516.6 Pa |
| 500 cmH₂O | 49,033.2 Pa |
| 1000 cmH₂O | 98,066.5 Pa |
| 5000 cmH₂O | 490,332 Pa |
Exact factor: 1 centimeter of water = 98.0665 pascals.
| Quantity | cmH₂O | Pa |
|---|---|---|
| Sea-level air | 1033 cmH₂O | 1.013e+05 Pa |
| A car tyre | 2250 cmH₂O | 2.206e+05 Pa |
| Blood pressure, systolic | 163.1 cmH₂O | 1.6e+04 Pa |
| A bicycle tyre | 6328 cmH₂O | 6.205e+05 Pa |
| A domestic water main | 4079 cmH₂O | 4e+05 Pa |
| A steam boiler | 1.02e+04 cmH₂O | 1e+06 Pa |
Published reference values, converted with the same factor this page uses.