Inches of Water to mmHg Converter

How to convert inches of water to millimeters of mercury

FormulammHg = inH₂O × 1.868320204

Multiply the value in inches of water by 1.868320204. To go the other way, multiply by 0.5352401575 (or divide by 1.868320204).

An inch of water is larger than a millimeter of mercury: one inch of water contains 1.868320204 millimeters of mercury.

Worked examples

1 inch of water1 inH₂O × 1.868320204 = 1.868320204 mmHg
5 inches of water5 inH₂O × 1.868320204 = 9.341601018 mmHg
10 inches of water10 inH₂O × 1.868320204 = 18.68320204 mmHg
20 inches of water20 inH₂O × 1.868320204 = 37.36640407 mmHg
100 inches of water100 inH₂O × 1.868320204 = 186.8320204 mmHg

Inches of water to millimeters of mercury conversion table

Values are calculated by the conversion engine and rounded to 8 significant figures.

Inches of water to millimeters of mercury: 0.1–10 inH₂O
Inches of water (inH₂O)	Millimeters of mercury (mmHg)
0.1 inH₂O	0.18683202 mmHg
0.25 inH₂O	0.46708005 mmHg
0.5 inH₂O	0.9341601 mmHg
1 inH₂O	1.8683202 mmHg
2 inH₂O	3.7366404 mmHg
3 inH₂O	5.6049606 mmHg
4 inH₂O	7.4732808 mmHg
5 inH₂O	9.341601 mmHg
6 inH₂O	11.209921 mmHg
7 inH₂O	13.078241 mmHg
8 inH₂O	14.946562 mmHg
9 inH₂O	16.814882 mmHg
10 inH₂O	18.683202 mmHg

Inches of water to millimeters of mercury: 12–1,000 inH₂O
Inches of water (inH₂O)	Millimeters of mercury (mmHg)
12 inH₂O	22.419842 mmHg
15 inH₂O	28.024803 mmHg
20 inH₂O	37.366404 mmHg
25 inH₂O	46.708005 mmHg
30 inH₂O	56.049606 mmHg
40 inH₂O	74.732808 mmHg
50 inH₂O	93.41601 mmHg
75 inH₂O	140.12402 mmHg
100 inH₂O	186.83202 mmHg
250 inH₂O	467.08005 mmHg
500 inH₂O	934.1601 mmHg
1,000 inH₂O	1,868.3202 mmHg

About the units

Inch of water (inH₂O)

Conventional value 249.08891 Pa. HVAC duct static pressure and gas-appliance pressures use inches of water column.

Millimeter of mercury (mmHg)

The conventional mmHg is 133.322387415 Pa. Blood pressure is measured in mmHg (e.g. 120/80).

Frequently asked questions

How many millimeters of mercury are in one inch of water?

There are 1.868320204 millimeters of mercury in one inch of water, and this value is exact by definition.

How do I convert inches of water to millimeters of mercury?

Multiply the number of inches of water by 1.868320204. For example, 10 inH₂O × 1.868320204 = 18.68320204 mmHg.

How many inches of water are in one millimeter of mercury?

One millimeter of mercury equals 0.5352401575 inches of water. That is the reverse factor, 1 ÷ 1.868320204.

What is 10 inches of water in millimeters of mercury?

10 inH₂O = 18.68320204 mmHg.

Is this inH₂O to mmHg converter accurate?

Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.