How to Convert Inches of mercury to Pascals (inHg 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 inches of mercury into pascals by hand, with examples and a quick-reference table.
The conversion
To convert inches of mercury to pascals, multiply the value by 3,386.389. To go the other way, divide by the same number (or multiply by 0.0002952998). For a quick estimate, multiply by about 3,400.
Pascals = inches of mercury × 3,386.389
Worked examples
- 3 inHg = 10,159.17 Pa
- 12.5 inHg = 42,329.86 Pa
- 75 inHg = 253,979.18 Pa
Inches of mercury to Pascals table
| Inches of mercury | Pascals |
|---|---|
| 1 inHg | 3,386.39 Pa |
| 2 inHg | 6,772.78 Pa |
| 5 inHg | 16,931.94 Pa |
| 10 inHg | 33,863.89 Pa |
| 20 inHg | 67,727.78 Pa |
| 25 inHg | 84,659.73 Pa |
| 50 inHg | 169,319.45 Pa |
| 100 inHg | 338,638.9 Pa |
| 250 inHg | 846,597.25 Pa |
| 500 inHg | 1,693,194.5 Pa |
| 1,000 inHg | 3,386,389 Pa |
Common questions
Is inHg 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 Inches of mercury converter.
Mistakes to avoid
Mixing similar-sounding units
US and imperial gallons, pints and tons are different sizes, and decimal kilobytes differ from binary kibibytes.
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.
Background
Singapore adopted the metric system in the 1970s, replacing imperial units and traditional Chinese measures in most official uses. Metric units are now standard in schools, trade and government, but older units survive in property, markets and imported goods.
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.
Many conversion factors are exact by definition. The inch has been defined as exactly 2.54 centimetres since 1959, and the pound as exactly 0.45359237 kilograms, so conversions involving them can be as precise as you need.
For any value, use the Inches of mercury to Pascals Converter or browse all pressure converters.
Run your own numbers: Inches of mercury to Pascals Converter