This page converts centimeters of water into torr using the factor 0.7355592401, and shows the reverse figure alongside it. Both units measure pressure, which is why one number does the whole job.
The unit ventilator and CPAP pressures are set in. One millimetre of mercury, used in vacuum work.
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. Two tables follow: rounded steps for quick lookup, and a set of real reference quantities converted into torr, which is usually more useful than the bare number.
The formula
centimeters of water- The amount you are converting, in centimeters of water
0.735559240069- The exact number of torr in one centimeter of water
torr- The converted result
How it works, step by step
- Enter the value in centimeters of water.
- It is multiplied by 0.735559240069, the exact factor between the two units.
- The answer is shown in torr, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
Blood pressure, systolic: 163 cmH₂O in torr
Take blood pressure, systolic, roughly 163 cmH₂O. The conversion is a single multiplication — 163 × 0.735559 — giving 119.896 Torr. Because the relationship is proportional, doubling the input doubles the answer to 239.792 Torr.
A steam boiler: 1.02e+04 cmH₂O in torr
At 1.02e+04 cmH₂O (a steam boiler), the same quantity in torr is 1.02e+04 × 0.735559 = 7502.7 Torr. One centimeter of water is 0.735559 torr, so the numbers shrink as expected.
How to read your score
Frequently asked questions
How many torr are in one centimeter of water?
Exactly 0.735559240069. 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 torr?
torr = centimeters of water × 0.735559240069. Reversed, centimeters of water = torr ÷ 0.735559240069, which is the same as multiplying by 1.35950980632.
Which is the bigger unit, the centimeter of water or the torr?
The torr. One centimeter of water is only 0.735559 of a torr, so it takes 1.35951 centimeters of water to make one torr.
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 torr?
One millimetre of mercury, used in vacuum work.
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 Torr in my head?
Plenty of people do this in their head: divide by 1.4 instead of using the exact factor 0.7355592401. At 100 that shortcut gives 71.428571 torr, off by 2.127 torr or about 2.89%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Centimeters Of Water to torr reference tables
| Centimeters Of Water | Torr |
|---|---|
| 0.5 cmH₂O | 0.36778 Torr |
| 1 cmH₂O | 0.735559 Torr |
| 2 cmH₂O | 1.47112 Torr |
| 3 cmH₂O | 2.20668 Torr |
| 5 cmH₂O | 3.6778 Torr |
| 10 cmH₂O | 7.35559 Torr |
| 20 cmH₂O | 14.7112 Torr |
| 25 cmH₂O | 18.389 Torr |
| 50 cmH₂O | 36.778 Torr |
| 75 cmH₂O | 55.1669 Torr |
| 100 cmH₂O | 73.5559 Torr |
| 250 cmH₂O | 183.89 Torr |
| 500 cmH₂O | 367.78 Torr |
| 1000 cmH₂O | 735.559 Torr |
| 5000 cmH₂O | 3677.8 Torr |
Exact factor: 1 centimeter of water = 0.735559240069 torr.
| Quantity | cmH₂O | Torr |
|---|---|---|
| Sea-level air | 1033 cmH₂O | 760 Torr |
| A car tyre | 2250 cmH₂O | 1655 Torr |
| Blood pressure, systolic | 163.1 cmH₂O | 120 Torr |
| A bicycle tyre | 6328 cmH₂O | 4654 Torr |
| A domestic water main | 4079 cmH₂O | 3000 Torr |
| A steam boiler | 1.02e+04 cmH₂O | 7501 Torr |
Published reference values, converted with the same factor this page uses.