How to Convert Millimetres of mercury to Pascals (mmHg to Pa)
Pressure conversions are used for tyre pressure (psi or bar), blood pressure readings in mmHg and weather maps in millibars. This guide shows how to convert millimetres of mercury into pascals by hand, with examples and a quick-reference table.
The conversion
To convert millimetres of mercury to pascals, multiply the value by 133.322. To go the other way, divide by the same number (or multiply by 0.0075006376). For a quick estimate, multiply by about 130.
Pascals = millimetres of mercury × 133.322
Worked examples
- 3 mmHg = 399.966 Pa
- 12.5 mmHg = 1,666.53 Pa
- 75 mmHg = 9,999.15 Pa
Millimetres of mercury to Pascals table
| Millimetres of mercury | Pascals |
|---|---|
| 1 mmHg | 133.322 Pa |
| 2 mmHg | 266.644 Pa |
| 5 mmHg | 666.61 Pa |
| 10 mmHg | 1,333.22 Pa |
| 20 mmHg | 2,666.44 Pa |
| 25 mmHg | 3,333.05 Pa |
| 50 mmHg | 6,666.1 Pa |
| 100 mmHg | 13,332.2 Pa |
| 250 mmHg | 33,330.5 Pa |
| 500 mmHg | 66,661 Pa |
| 1,000 mmHg | 133,322 Pa |
Common questions
Is mmHg to Pa exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the Pascals to Millimetres of mercury converter.
Mistakes to avoid
Rounding the factor too early
Using 3 instead of 3.28 for feet per metre introduces an error of almost 9% before you have started.
Multiplying when you should divide
Converting to a smaller unit gives a bigger number, and converting to a larger unit gives a smaller one. If your answer moves the wrong way, you have inverted the factor.
Forgetting squared and cubed units
Area and volume factors are the length factor squared or cubed, so 1 m² is about 10.76 sq ft, not 3.28.
Background
Writing the units next to every number while you work is the simplest way to avoid mistakes. If the units do not cancel to leave the one you want, the calculation is set up wrongly.
Unit conversion is simply multiplication by a fixed ratio. The ratio between two units of the same quantity never changes, so once you know it you can convert any value in either direction.
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
For any value, use the Millimetres of mercury to Pascals Converter or browse all pressure converters.
Run your own numbers: Millimetres of mercury to Pascals Converter