How to Convert Millibars to Inches of mercury (mbar 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 millibars into inches of mercury by hand, with examples and a quick-reference table.
The conversion
To convert millibars to inches of mercury, multiply the value by 0.0295299802. To go the other way, divide by the same number (or multiply by 33.86389). For a quick estimate, multiply by about 0.03.
Inches of mercury = millibars × 0.0295299802
Worked examples
- 3 mbar = 0.08859 inHg
- 12.5 mbar = 0.369125 inHg
- 75 mbar = 2.2147 inHg
Millibars to Inches of mercury table
| Millibars | Inches of mercury |
|---|---|
| 1 mbar | 0.02953 inHg |
| 2 mbar | 0.05906 inHg |
| 5 mbar | 0.14765 inHg |
| 10 mbar | 0.2953 inHg |
| 20 mbar | 0.5906 inHg |
| 25 mbar | 0.73825 inHg |
| 50 mbar | 1.4765 inHg |
| 100 mbar | 2.953 inHg |
| 250 mbar | 7.3825 inHg |
| 500 mbar | 14.765 inHg |
| 1,000 mbar | 29.53 inHg |
Common questions
Is mbar 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 Millibars 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.
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.
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
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.
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 any value, use the Millibars to Inches of mercury Converter or browse all pressure converters.
Run your own numbers: Millibars to Inches of mercury Converter