To convert inches of water to kilogram-force per square centimeter, multiply by 0.002539999898. That factor is the whole relationship: both units measure pressure, so the conversion is a proportion with no offset and no substance-specific constant.
The low-pressure unit for duct static pressure and gas appliances in the US. Legacy metric engineering unit, still common in Asia.
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 kilogram-force per square centimeter so the number you get has something to be compared against.
The formula
inches of water- The amount you are converting, in inches of water
0.00253999989803- The exact number of kilogram-force per square centimeter in one inch of water
kilogram-force per square centimeter- The converted result
How it works, step by step
- Enter the value in inches of water.
- It is multiplied by 0.00253999989803, the exact factor between the two units.
- The answer is shown in kilogram-force per square centimeter, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
A domestic water main: 1610 inH₂O in kilogram-force per square centimeter
A domestic water main comes to about 1610 inH₂O. Multiplying by the factor: 1610 × 0.00254 = 4.0894 kgf/cm². Dividing the answer back by 0.00254 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
Blood pressure, systolic: 64.2 inH₂O in kilogram-force per square centimeter
At 64.2 inH₂O (blood pressure, systolic), the same quantity in kilogram-force per square centimeter is 64.2 × 0.00254 = 0.163068 kgf/cm². One inch of water is 0.00254 kilogram-force per square centimeter, so the numbers shrink as expected.
How to read your score
Frequently asked questions
How many kilogram-force per square centimeter are in one inch of water?
Exactly 0.00253999989803. 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 inches of water to kilogram-force per square centimeter?
kilogram-force per square centimeter = inches of water × 0.00253999989803. Reversed, inches of water = kilogram-force per square centimeter ÷ 0.00253999989803, which is the same as multiplying by 393.700803207.
Which is the bigger unit, the inch of water or the kilogram-force per square centimeter?
The kilogram-force per square centimeter. One inch of water is only 0.00254 of a kilogram-force per square centimeter, so it takes 393.701 inches of water to make one kilogram-force per square centimeter.
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 inch of water?
The low-pressure unit for duct static pressure and gas appliances in the US.
What is a kilogram-force per square centimeter?
Legacy metric engineering unit, still common in Asia.
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 inH₂O to kgf/cm² in my head?
Plenty of people do this in their head: divide by 400 instead of using the exact factor 0.002539999898. At 100 that shortcut gives 0.25 kilogram-force per square centimeter, off by 0.004 kilogram-force per square centimeter or about 1.57%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Inches Of Water to kilogram-force per square centimeter reference tables
| Inches Of Water | Kilogram-Force Per Square Centimeter |
|---|---|
| 0.5 inH₂O | 0.00127 kgf/cm² |
| 1 inH₂O | 0.00254 kgf/cm² |
| 2 inH₂O | 0.00508 kgf/cm² |
| 3 inH₂O | 0.00762 kgf/cm² |
| 5 inH₂O | 0.0127 kgf/cm² |
| 10 inH₂O | 0.0254 kgf/cm² |
| 20 inH₂O | 0.0508 kgf/cm² |
| 25 inH₂O | 0.0635 kgf/cm² |
| 50 inH₂O | 0.127 kgf/cm² |
| 75 inH₂O | 0.1905 kgf/cm² |
| 100 inH₂O | 0.254 kgf/cm² |
| 250 inH₂O | 0.635 kgf/cm² |
| 500 inH₂O | 1.27 kgf/cm² |
| 1000 inH₂O | 2.54 kgf/cm² |
| 5000 inH₂O | 12.7 kgf/cm² |
Exact factor: 1 inch of water = 0.00253999989803 kilogram-force per square centimeter.
| Quantity | inH₂O | kgf/cm² |
|---|---|---|
| Sea-level air | 406.8 inH₂O | 1.033 kgf/cm² |
| A car tyre | 885.8 inH₂O | 2.25 kgf/cm² |
| Blood pressure, systolic | 64.23 inH₂O | 0.1631 kgf/cm² |
| A bicycle tyre | 2491 inH₂O | 6.328 kgf/cm² |
| A domestic water main | 1606 inH₂O | 4.079 kgf/cm² |
| A steam boiler | 4015 inH₂O | 10.2 kgf/cm² |
Published reference values, converted with the same factor this page uses.