20 inHg is equal to approximately 6779.95 mbar.
To convert inches of mercury (inHg) to millibar (mbar), multiply the value in inHg by 33.8639, because 1 inHg equals 33.8639 mbar. So, 20 inHg times 33.8639 gives about 6779.95 mbar.
Conversion Tool
Result in mbar:
Conversion Formula
The formula to convert inches of mercury (inHg) to millibar (mbar) is:
mbar = inHg × 33.8639
This works because 1 inch of mercury equals exactly 33.8639 millibars. Inches of mercury measure pressure based on the height of a mercury column in a barometer, while millibar is a metric unit of pressure. Multiplying the inHg value by 33.8639 converts it directly into mbar.
Example calculation for 20 inHg:
- Start with 20 inHg
- Multiply 20 × 33.8639 = 677.278 mbar
- The result is 677.278 mbar
Conversion Example
- 15 inHg to mbar
- Multiply 15 × 33.8639
- = 507.9585 mbar
- So, 15 inHg is about 507.9585 mbar
- 5 inHg to mbar
- 5 × 33.8639 = 169.3195 mbar
- Therefore 5 inHg equals around 169.3195 mbar
- 30 inHg to mbar
- Multiply 30 × 33.8639
- = 1015.917 mbar
- 30 inHg converts to 1015.917 mbar
- 0 inHg to mbar
- 0 × 33.8639 = 0 mbar
- Zero inHg means zero millibar
Conversion Chart
| inHg | mbar |
|---|---|
| -5.0 | -169.3195 |
| 0.0 | 0.0000 |
| 5.0 | 169.3195 |
| 10.0 | 338.6390 |
| 15.0 | 507.9585 |
| 20.0 | 677.2780 |
| 25.0 | 846.5975 |
| 30.0 | 1015.9170 |
| 35.0 | 1185.2365 |
| 40.0 | 1354.5560 |
| 45.0 | 1523.8755 |
The chart above shows inHg values in the left column, with their equivalents in mbar in the right column. To use it, find the inHg value closest to what you need and read across for the mbar equivalent. Negative values represent pressures below atmospheric pressure.
Related Conversion Questions
- How many mbar is 20 inches of mercury?
- What is the pressure in mbar when the barometer reads 20 inHg?
- How do you convert 20 inHg to millibars?
- Is 20 inHg a high or low pressure in mbar?
- What formula converts 20 inHg into mbar?
- Can I convert 20 inHg to mbar without a calculator?
- What is 20 inHg expressed in millibars for weather data?
Conversion Definitions
inhg: Inches of mercury (inHg) is a unit of pressure measuring the height of a mercury column in a barometer, commonly used in the United States for atmospheric pressure. One inHg equals the pressure exerted by a mercury column one inch high at standard gravity and temperature conditions.
mbar: Millibar (mbar) is a metric unit of pressure widely used in meteorology and science, equal to 100 pascals. It represents force per unit area and is convenient for expressing atmospheric pressure, weather reports, and altimeter settings in aviation and other fields.
Conversion FAQs
Why is the conversion factor 33.8639 used between inHg and mbar?
The factor 33.8639 comes from the precise physical relationship between the pressure exerted by a mercury column one inch high and the millibar unit. Mercury’s density, gravity, and unit conversions between inches and meters define this constant. Using it converts pressure measured in inHg directly into mbar.
Can I convert negative values of inHg to mbar?
Yes, negative inHg values represent pressures below a reference point, like vacuum conditions. Multiplying a negative inHg by 33.8639 gives a negative millibar value, which indicates below atmospheric pressure or a partial vacuum, depending on context.
Are inHg and mbar interchangeable for all pressure measurements?
They both measure pressure but are not interchangeable without conversion. inHg is common in certain countries and applications like aviation and older meteorological data, while mbar is metric and more universal. You must convert values when switching units to keep accuracy.
Does temperature affect the inHg to mbar conversion?
The standard conversion assumes standard temperature and gravity conditions because mercury density depends on temperature. Large temperature variations may slightly affect pressure readings in inHg, but for most practical purposes, the fixed conversion factor 33.8639 is accurate enough.
How precise is the inHg to mbar conversion?
Using 33.8639 as the multiplication factor yields a conversion precise to four decimal places, which is sufficient for weather reports and most applications. For extreme scientific measurements, tiny variations due to environmental factors might require more detailed calculation methods.