How to Convert PSI to Inches of mercury (psi to inHg)
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 psi into inches of mercury by hand, with examples and a quick-reference table.
The conversion
To convert psi to inches of mercury, multiply the value by 2.0360203745. To go the other way, divide by the same number (or multiply by 0.4911542205). For a quick estimate, multiply by about 2.
Inches of mercury = psi × 2.0360203745
Worked examples
- 3 psi = 6.1081 inHg
- 12.5 psi = 25.4503 inHg
- 75 psi = 152.7015 inHg
PSI to Inches of mercury table
| PSI | Inches of mercury |
|---|---|
| 1 psi | 2.036 inHg |
| 2 psi | 4.072 inHg |
| 5 psi | 10.1801 inHg |
| 10 psi | 20.3602 inHg |
| 20 psi | 40.7204 inHg |
| 25 psi | 50.9005 inHg |
| 50 psi | 101.801 inHg |
| 100 psi | 203.602 inHg |
| 250 psi | 509.0051 inHg |
| 500 psi | 1,018.01 inHg |
| 1,000 psi | 2,036.02 inHg |
Common questions
Is psi to inHg 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 Inches of mercury to PSI converter.
Mistakes to avoid
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.
Mixing similar-sounding units
US and imperial gallons, pints and tons are different sizes, and decimal kilobytes differ from binary kibibytes.
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
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.
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.
For everyday use, three or four significant figures are usually enough. Engineering, science and trade documents may need more, and rounding should happen only at the end of a calculation.
For any value, use the PSI to Inches of mercury Converter or browse all pressure converters.
Run your own numbers: PSI to Inches of mercury Converter