Centimetres of water to Millimetres of mercury
Type a value in Centimetres of water and get the result in Millimetres of mercury, calculated exactly.
1 Centimetres of water ≈ 0.7355591353 Millimetres of mercury
Precision
Conventional factorRounded for display to about 10 significant digits.
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Formula
mmHg = cmH₂O ÷ 1.35951
To convert Centimetres of water to Millimetres of mercury, divide the value by 1.35951.
Worked examples
- 1 cmH₂O ÷ 1.35951 ≈ 0.7355591353 mmHg
- 100 cmH₂O ÷ 1.35951 ≈ 73.55591353 mmHg
- 50 cmH₂O ÷ 1.35951 ≈ 36.77795676 mmHg
This factor rests on a conventional or rounded value.
Conversion table
| Centimetres of water (cmH₂O) | Millimetres of mercury (mmHg) |
|---|---|
| 1 | ≈ 0.7355591 |
| 2 | ≈ 1.471118 |
| 3 | ≈ 2.206677 |
| 4 | ≈ 2.942237 |
| 5 | ≈ 3.677796 |
| 6 | ≈ 4.413355 |
| 7 | ≈ 5.148914 |
| 8 | ≈ 5.884473 |
| 9 | ≈ 6.620032 |
| 10 | ≈ 7.355591 |
| 15 | ≈ 11.03339 |
| 20 | ≈ 14.71118 |
| 25 | ≈ 18.38898 |
| 30 | ≈ 22.06677 |
| 40 | ≈ 29.42237 |
| 50 | ≈ 36.77796 |
| 60 | ≈ 44.13355 |
| 70 | ≈ 51.48914 |
| 75 | ≈ 55.16694 |
| 80 | ≈ 58.84473 |
| 90 | ≈ 66.20032 |
| 100 | ≈ 73.55591 |
Values marked ≈ are rounded; the rest are exact.
Reverse table: Millimetres of mercury to Centimetres of water
| Millimetres of mercury (mmHg) | Centimetres of water (cmH₂O) |
|---|---|
| 1 | 1.35951 |
| 2 | 2.71902 |
| 3 | 4.07853 |
| 4 | 5.43804 |
| 5 | 6.79755 |
| 6 | 8.15706 |
| 7 | 9.51657 |
| 8 | 10.87608 |
| 9 | 12.23559 |
| 10 | 13.5951 |
| 15 | 20.39265 |
| 20 | 27.1902 |
| 25 | 33.98775 |
| 30 | 40.7853 |
| 40 | 54.3804 |
| 50 | 67.9755 |
| 60 | 81.5706 |
| 70 | 95.1657 |
| 75 | 101.96325 |
| 80 | 108.7608 |
| 90 | 122.3559 |
| 100 | 135.951 |
Unit definitions
- Centimetres of water cmH₂O
- Conventional value of 98.0665 pascals, used for ventilators and CPAP.
- Millimetres of mercury mmHg
- The conventional value of 133.322387415 pascals, used for blood pressure.
Questions people ask
Centimetres of water to Millimetres of mercury: what is the conversion factor?
One cmH₂O is ≈ 0.7355591353 mmHg.
How do I convert Centimetres of water to Millimetres of mercury?
Use the formula above. For example, 100 cmH₂O = ≈ 73.55591353 mmHg.
Is the conversion exact?
Very nearly. One of the units is based on a conventional or rounded value, so treat the result as a close approximation.
Factors checked 19 October 2026.