The inch of mercury
The inch of mercury (inHg) equals 3,386.389 Pa under the NIST SP 811 conventional definition. It is the standard unit for barometric pressure on US weather reports and for altimeter settings in US aviation.
Inches of mercury to Pounds per square inch
1 inHg = 0.491154 psi (inch of mercury → pound per square inch)
1 inHg = 0.491154 psi
1 inch of mercury equals 0.491154 pounds per square inch. To convert inches of mercury to pounds per square inch, multiply the inch of mercury value by 0.491154. For quick reference: 1 inHg = 0.491154 psi, 5 inHg = 2.45577 psi, 10 inHg = 4.91154 psi, 100 inHg = 49.1154 psi.
Formula
Pounds per square inch = Inches of mercury × 0.491154Quick
How to convert inches of mercury to pounds per square inch
Take your value
Start with your value in inches of mercury.
Multiply by 0.491154
Multiply the inch of mercury value by 0.491154. This is the exact conversion factor from inches of mercury to pounds per square inch.
Read the result
The product is your value in pounds per square inch. For example, 5 inHg × 0.491154 = 2.45577 psi.
Conversion formula
The exact factor from inches of mercury to pounds per square inch is 0.491154.
Pounds per square inch = Inches of mercury × 0.491154
Inches of mercury to Pounds per square inch conversion table
Fifty common reference values, hand-picked for skim utility. Use the calculator above for any value not listed.
| Inches of mercury (inHg) | Pounds per square inch (psi) |
|---|---|
| 0.001 inHg | 0.00049115 psi |
| 0.01 inHg | 0.0049115 psi |
| 0.1 inHg | 0.049115 psi |
| 0.5 inHg | 0.24558 psi |
| 1 inHg | 0.49115 psi |
| 1.5 inHg | 0.73673 psi |
| 2 inHg | 0.98231 psi |
| 2.5 inHg | 1.2279 psi |
| 3 inHg | 1.4735 psi |
| 4 inHg | 1.9646 psi |
| 5 inHg | 2.4558 psi |
| 6 inHg | 2.9469 psi |
| 7 inHg | 3.4381 psi |
| 8 inHg | 3.9292 psi |
| 9 inHg | 4.4204 psi |
| 10 inHg | 4.9115 psi |
| 14 inHg | 6.8762 psi |
| 15 inHg | 7.3673 psi |
| 20 inHg | 9.8231 psi |
| 25 inHg | 12.279 psi |
| 30 inHg | 14.735 psi |
| 32 inHg | 15.717 psi |
| 35 inHg | 17.19 psi |
| 40 inHg | 19.646 psi |
| 50 inHg | 24.558 psi |
| 60 inHg | 29.469 psi |
| 75 inHg | 36.837 psi |
| 80 inHg | 39.292 psi |
| 100 inHg | 49.115 psi |
| 101.325 inHg | 49.766 psi |
| 150 inHg | 73.673 psi |
| 200 inHg | 98.231 psi |
| 250 inHg | 122.79 psi |
| 300 inHg | 147.35 psi |
| 400 inHg | 196.46 psi |
| 500 inHg | 245.58 psi |
| 760 inHg | 373.28 psi |
| 1000 inHg | 491.15 psi |
| 1013.25 inHg | 497.66 psi |
| 2000 inHg | 982.31 psi |
| 5000 inHg | 2455.8 psi |
| 10000 inHg | 4911.5 psi |
| 14.7 inHg | 7.22 psi |
| 50000 inHg | 24558 psi |
| 100000 inHg | 49115 psi |
| 101325 inHg | 49766 psi |
| 200000 inHg | 98231 psi |
| 500000 inHg | 245577 psi |
| 1000000 inHg | 491154 psi |
| 10000000 inHg | 4911542 psi |
Real-world reference
Standard atmospheric pressure is 29.92 inHg. US weather reports typically quote barometric pressure in inHg. In pounds per square inch, that gives you: 1 inHg = 0.491154 psi, 10 inHg = 4.91154 psi, 100 inHg = 49.1154 psi.
Frequently asked questions
- How many pounds per square inch are in 1 inch of mercury?
- 1 inch of mercury equals 0.491154 pounds per square inch.
- How do I convert inches of mercury to pounds per square inch?
- Multiply the inch of mercury value by 0.491154. So x inHg × 0.491154 = the equivalent in psi.
- What is 5 inches of mercury in pounds per square inch?
- 5 inches of mercury equals 2.45577 pounds per square inch.
- What is 10 inches of mercury in pounds per square inch?
- 10 inches of mercury equals 4.91154 pounds per square inch.
- What is 100 inches of mercury in pounds per square inch?
- 100 inches of mercury equals 49.1154 pounds per square inch.
- How do I convert back from pounds per square inch to inches of mercury?
- Multiply the pound per square inch value by 2.03602. For example, 1 psi = 2.03602 inHg.
- Is the inch of mercury bigger than the pound per square inch?
- No. 1 inch of mercury is smaller than 1 pound per square inch. It takes 2.03602 inches of mercury to equal 1 pound per square inch.
- Are these conversion factors exact?
- The factor is derived directly from the SI definitions of inch of mercury and pound per square inch; the displayed value is rounded for readability, and the browser computes using IEEE 754 double-precision arithmetic.
About the inch of mercury and the pound per square inch
The pound per square inch
The pound per square inch (psi) is the customary US pressure unit, derived from the avoirdupois pound-force on a square inch (≈ 6,894.76 Pa exactly). It is the standard unit on US car tire-pressure stickers, scuba gauges in the US, and most plumbing specifications.