Inches of Mercury to Millibar Converter
Convert from Inches of Mercury (inHg) to Millibar (mbar)
Understanding Inches of Mercury and Millibar
Inches of mercury (inHg) is a unit of pressure used in meteorology and aviation in the United States.
- Based on the height of a mercury column in a barometer
- Standard atmospheric pressure is approximately 29.92 inHg
- Common on weather reports and altimeters in the US
The millibar (mbar) is a metric unit of pressure equal to 1/1000 of a bar.
- 1 mbar = 100 pascals (Pa) = 0.1 kPa
- Standard atmospheric pressure is approximately 1013.25 mbar
- Widely used in meteorology worldwide, especially in weather forecasting
Conversion Formula
inHg to mbar:
mbar = inHg × 33.8639
To convert from inches of mercury to millibars, multiply the inHg value by approximately 33.8639.
mbar to inHg:
inHg = mbar × 0.02953
To convert from millibars to inches of mercury, multiply the mbar value by approximately 0.02953.
inHg to Millibar Conversion Table
| Inches of Mercury (inHg) | Millibar (mbar) |
|---|---|
| 29.00 | 982 |
| 29.50 | 999 |
| 30.00 | 1016 |
| 30.50 | 1033 |
| 31.00 | 1050 |
| 31.50 | 1067 |
| 32.00 | 1084 |
| 32.50 | 1101 |
| 33.00 | 1118 |
| 33.50 | 1134 |
Historical Context and Applications
Historical Development
The mercury barometer was invented by Evangelista Torricelli in 1643, and inches of mercury became a standard way to measure atmospheric pressure. The unit is based on the height of mercury in a glass tube in a barometer. The millibar, on the other hand, is a more recent metric unit that emerged with the adoption of the CGS and later SI systems. Today, meteorologists around the world use millibars, while inches of mercury remains common in the United States.
Common Applications
- inHg: Used in US weather forecasts, aviation altimeters and barometers, and some industrial applications in North America.
- mbar: Standard unit for meteorological reporting worldwide, used on weather maps and in forecasting models. Also used in various scientific and engineering applications.
Practical Examples
- Standard atmospheric pressure: 29.92 inHg (1013.25 mbar)
- Strong hurricane core: <27.30 inHg (<925 mbar)
- Strong high pressure system: 30.50 inHg (1033 mbar)
- Typical low pressure system: 29.50 inHg (999 mbar)
- Pressure at 18,000 feet altitude: 15.00 inHg (508 mbar)
- Enter your value in the inches of mercury (inHg) field
- The converter instantly displays the equivalent in millibars
- Use the swap button to convert from millibars to inches of mercury instead
- Results are displayed with 6 decimal places for precision
For quick reference without calculations, refer to the conversion table above for common values.