This page converts centimeters of water into pounds per square foot using the factor 2.048161436, and shows the reverse figure alongside it. Both units measure pressure, which is why one number does the whole job.
The unit US building codes give floor, roof and wind loads in. 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 pounds per square foot, 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
2.04816143623- The exact number of pounds per square foot in one centimeter of water
pounds per square foot- The converted result
How it works, step by step
- Enter the value in centimeters of water.
- It is multiplied by 2.04816143623, the exact factor between the two units.
- The answer is shown in pounds per square foot, 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 pounds per square foot
A car tyre comes to about 2250 cmH₂O. Multiplying by the factor: 2250 × 2.04816 = 4608.36 psf. Dividing the answer back by 2.04816 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
Sea-level air: 1030 cmH₂O in pounds per square foot
Sea-level air comes to about 1030 cmH₂O. Multiplying by the factor: 1030 × 2.04816 = 2109.61 psf. Dividing the answer back by 2.04816 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 pounds per square foot are in one centimeter of water?
Exactly 2.04816143623. 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 pounds per square foot?
pounds per square foot = centimeters of water × 2.04816143623. Reversed, centimeters of water = pounds per square foot ÷ 2.04816143623, which is the same as multiplying by 0.488242763638.
Which is the bigger unit, the centimeter of water or the pound per square foot?
The centimeter of water. One centimeter of water equals 2.04816 pounds per square foot.
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 pound per square foot?
The unit US building codes give floor, roof and wind loads in.
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 psf in my head?
Plenty of people do this in their head: multiply by 2 instead of using the exact factor 2.048161436. At 100 that shortcut gives 200 pounds per square foot, off by 4.816 pounds per square foot or about 2.35%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Centimeters Of Water to pounds per square foot reference tables
| Centimeters Of Water | Pounds Per Square Foot |
|---|---|
| 0.5 cmH₂O | 1.02408 psf |
| 1 cmH₂O | 2.04816 psf |
| 2 cmH₂O | 4.09632 psf |
| 3 cmH₂O | 6.14448 psf |
| 5 cmH₂O | 10.2408 psf |
| 10 cmH₂O | 20.4816 psf |
| 20 cmH₂O | 40.9632 psf |
| 25 cmH₂O | 51.204 psf |
| 50 cmH₂O | 102.408 psf |
| 75 cmH₂O | 153.612 psf |
| 100 cmH₂O | 204.816 psf |
| 250 cmH₂O | 512.04 psf |
| 500 cmH₂O | 1024.08 psf |
| 1000 cmH₂O | 2048.16 psf |
| 5000 cmH₂O | 10,240.8 psf |
Exact factor: 1 centimeter of water = 2.04816143623 pounds per square foot.
| Quantity | cmH₂O | psf |
|---|---|---|
| Sea-level air | 1033 cmH₂O | 2116 psf |
| A car tyre | 2250 cmH₂O | 4608 psf |
| Blood pressure, systolic | 163.1 cmH₂O | 334.1 psf |
| A bicycle tyre | 6328 cmH₂O | 1.296e+04 psf |
| A domestic water main | 4079 cmH₂O | 8354 psf |
| A steam boiler | 1.02e+04 cmH₂O | 2.089e+04 psf |
Published reference values, converted with the same factor this page uses.