Inches Of Mercury to Millibars
Inches of mercury measure pressure the same way as mmHg but in inches, commonly used for barometric pressure in US weather reports. A millibar is one thousandth of a bar, the standard unit meteorologists use for barometric pressure readings. 1 inHg equals ≈33.8639 mbar, so converting between them is a matter of multiplying by that fixed factor — type any value into the converter below and both sides update instantly as you type.
Both units belong to pressure, measured here against pressure's base unit (Pa) — every other pressure unit on this site converts through that same reference point, which is why the table below can also be read as a quick cross-check against nearby values.
Formula
mbar = inHg × ≈33.8639
inHg = mbar × ≈0.02953
Worked example: 5 inHg × ≈33.8639 = ≈169.319 mbar.
Conversion table
| Inch of Mercury (inHg) | Millibar (mbar) |
|---|---|
| 1 inHg | ≈33.8639 mbar |
| 2 inHg | ≈67.7278 mbar |
| 3 inHg | ≈101.592 mbar |
| 5 inHg | ≈169.319 mbar |
| 10 inHg | ≈338.639 mbar |
| 20 inHg | ≈677.278 mbar |
| 25 inHg | ≈846.597 mbar |
| 50 inHg | ≈1,693.19 mbar |
| 100 inHg | ≈3,386.39 mbar |
| 250 inHg | ≈8,465.97 mbar |
| 500 inHg | ≈16,931.9 mbar |
| 1,000 inHg | ≈33,863.9 mbar |
Frequently asked
- How many Millibars in a inch of mercury?
- 1 inHg equals ≈33.8639 mbar.
- How do I convert Inches of Mercury to Millibars?
- Multiply the value in inHg by ≈33.8639 to get mbar. The converter above does this instantly as you type.
- Is the conversion exact?
- Yes — Inch of Mercury and Millibar are both defined by a fixed conversion factor to pressure's base unit (Pa), so the result shown is exact to the precision displayed, not an approximation.