Inches of mercury to millibar
Type a value in inches of mercury to see it in millibar straight away, or type in the second box to convert back.
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How to use it
- Type the value in the inches of mercury box.
- Read the result in millibar as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
mbar = inHg × 33.8638864
Multiply the value in inches of mercury by 33.8638864 to get millibar.
Example
To convert 25 inHg to millibar: 25 × 33.8638864 = 846.597 mbar.
Conversion table
| Inches of mercury (inHg) | Millibar (mbar) |
|---|---|
| 1 | 33.8639 |
| 2 | 67.7278 |
| 3 | 101.592 |
| 5 | 169.319 |
| 10 | 338.639 |
| 20 | 677.278 |
| 25 | 846.597 |
| 50 | 1,693.19 |
| 100 | 3,386.39 |
| 250 | 8,465.97 |
| 500 | 16,931.9 |
| 1,000 | 33,863.9 |
About the units
- Inch of mercury
- The pressure of a one inch mercury column at conventional density and standard gravity, about 3386.389 Pa. Common in aviation and US weather reports.
- Millibar
- One thousandth of a bar, exactly 100 pascals, the same as one hectopascal.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many millibar are in one inch of mercury?
1 inHg = 33.8639 mbar exactly.
How do I convert inches of mercury to millibar?
Use mbar = inHg × 33.8638864. For example, 25 inHg = 846.597 mbar.
How many inches of mercury are in one millibar?
1 mbar = 0.02953 inHg.
What is the difference between gauge and absolute pressure?
Gauge pressure is measured from the surrounding air pressure, while absolute pressure starts from a perfect vacuum. These converters change the unit only, so a gauge reading stays a gauge reading.
Are torr and mmHg the same?
Almost. One torr is 101325/760 Pa, about 133.322368 Pa, and one conventional mmHg is 133.322387 Pa, a difference of less than one part per million. For everyday use you can treat them as equal.