This converter turns millibars into inches of mercury instantly, using the exact factor 1 millibar = 0.02952998016 inches of mercury. Type any number and the result updates as you go — nothing is sent to a server, so the arithmetic happens entirely in your browser.
The meteorologist’s unit — sea-level pressure averages 1013.25 mbar. US aviation and weather altimeter setting unit.
Because the relationship is a simple proportion, one multiplication does the whole job. The table further down gives pre-computed values for the amounts people look up most often, and the result panel also reports the reverse conversion so you can check the figure both ways.
The formula
millibars- The amount you are converting, measured in millibars
0.02952998016- The exact number of inches of mercury in one millibar
inches of mercury- The converted result
How it works, step by step
- Enter the number of millibars you want to convert.
- The value is multiplied by 0.02952998016, the exact conversion factor.
- The result is displayed in inches of mercury, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 millibars
Multiply 5 by 0.02952998. That gives 0.14765 inches of mercury. A quick sanity check: one millibar is smaller than one inch of mercury, so the number should get smaller — and it does.
Converting 72 millibars
72 × 0.02952998 = 2.1262 inches of mercury. Working backwards, 2.1262 ÷ 0.02952998 returns 72 millibars, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many inches of mercury are in one millibar?
Exactly 0.02952998016. Every conversion on this page is that single number multiplied by your input, so the result carries no rounding error beyond what is shown.
What is the formula to convert millibars to inches of mercury?
Inches Of Mercury = millibars × 0.02952998016. To reverse it, divide instead: millibars = inches of mercury ÷ 0.02952998016, which is the same as multiplying by 33.86389.
Is the millibar bigger than the inch of mercury?
No. One millibar is only 0.02953 of a inch of mercury, so the inch of mercury is the larger unit.
Why does my answer differ slightly from other millibar to inhg converters?
Most differences come from rounding the factor too early. This tool keeps full double precision through the calculation and only rounds at the final display step, and it also shows the unrounded value so you can see exactly where any difference appears.
What is a millibar?
The meteorologist’s unit — sea-level pressure averages 1013.25 mbar.
What is a inch of mercury?
US aviation and weather altimeter setting unit.
Millibars to inches of mercury reference table
| Millibars | Inches Of Mercury |
|---|---|
| 0.5 mbar | 0.014765 inHg |
| 1 mbar | 0.02953 inHg |
| 2 mbar | 0.05906 inHg |
| 3 mbar | 0.08859 inHg |
| 5 mbar | 0.14765 inHg |
| 10 mbar | 0.2953 inHg |
| 15 mbar | 0.44295 inHg |
| 20 mbar | 0.5906 inHg |
| 25 mbar | 0.73825 inHg |
| 50 mbar | 1.4765 inHg |
| 75 mbar | 2.2147 inHg |
| 100 mbar | 2.953 inHg |
| 250 mbar | 7.3825 inHg |
| 500 mbar | 14.765 inHg |
| 1000 mbar | 29.53 inHg |
Exact factor: 1 millibar = 0.02952998016 inches of mercury. Values rounded for display.