How to convert hectopascals to inches of mercury
One hectopascal equals 0.02953 inches of mercury, so multiply the number of hectopascals by 0.02953:
inHg = hPa × 0.02953
hPa = inHg ÷ 0.02953 (1 inHg = 33.8639 hPa)
Example: 980 hPa → 980 × 0.02953 = 28.9394 inHg.
Going the other way, divide by 0.02953, or multiply by 33.8639; the inches of mercury to hectopascals converter does it for you.
Everyday values
| Hectopascals | Inches of mercury | For example |
|---|---|---|
| 980 hPa | 28.9394 inHg | a deep low-pressure system |
| 1,000 hPa | 29.53 inHg | 1,000 hPa |
| 1,013.25 hPa | 29.9213 inHg | standard sea-level pressure |
| 1,030 hPa | 30.4159 inHg | a strong high-pressure system |
When you need this conversion
Weather maps worldwide show air pressure in hectopascals (identical to millibars); US weather reports and aircraft altimeters in North America use inches of mercury. Standard pressure is 1013.25 hPa, or 29.92 inHg.
Hectopascal to inch of mercury conversion table
| hPa | inHg | hPa | inHg |
|---|---|---|---|
| 950 hPa | 28.0535 inHg | 1,000 hPa | 29.53 inHg |
| 955 hPa | 28.2011 inHg | 1,005 hPa | 29.6776 inHg |
| 960 hPa | 28.3488 inHg | 1,010 hPa | 29.8253 inHg |
| 965 hPa | 28.4964 inHg | 1,015 hPa | 29.9729 inHg |
| 970 hPa | 28.6441 inHg | 1,020 hPa | 30.1206 inHg |
| 975 hPa | 28.7917 inHg | 1,025 hPa | 30.2682 inHg |
| 980 hPa | 28.9394 inHg | 1,030 hPa | 30.4159 inHg |
| 985 hPa | 29.087 inHg | 1,035 hPa | 30.5635 inHg |
| 990 hPa | 29.2347 inHg | 1,040 hPa | 30.7112 inHg |
| 995 hPa | 29.3823 inHg | 1,045 hPa | 30.8588 inHg |
About the units
- Hectopascal (hPa): 100 pascals, identical to the millibar used in weather reports.
- Inch of mercury (inHg): the pressure of a 1-inch column of mercury, about 3,386.39 Pa.
Both are units of pressure. The conversion factor comes from the exact definitions above, so the calculator is exact; results are only rounded for display (up to six significant digits).
Frequently asked questions
How many inches of mercury are in one hectopascal?
One hectopascal is 0.02953 inches of mercury. One inch of mercury is 33.8639 hectopascals.
How do I convert hectopascals to inches of mercury?
Multiply the value in hectopascals by 0.02953. To go back, divide by 0.02953.
What is 980 hPa in inches of mercury?
980 hPa = 28.9394 inHg.
What is 1,000 hPa in inches of mercury?
1,000 hPa = 29.53 inHg.
Sources
- NIST Special Publication 811 (2008), Guide for the Use of the International System of Units (SI), Appendix B: conversion factors.
- NIST Handbook 44 (2024), Appendix C: General tables of units of measurement.
Last reviewed 5 October 2026. Results are estimates; see our disclaimer.