Convert inches of mercury to psi

1 inHg=0.4912psi

Use the converter below to change any inches of mercury value into psi instantly — with formula, conversion table, and real-world examples.

You have

Equals

0.49115

Conversion formula

Forward

psi = inches of mercury × 0.4912

Reverse

inches of mercury = psi × 2.03602

Example: 10 inHg × 0.4912 = 4.91154 psi.

About both units

From

Inch of Mercury

inHg

The inch of mercury equals about 3386 Pa. Used in US barometers, US aviation altimeter settings and some engineering. Standard sea-level pressure: 29.92 inHg.

Real-world: Sea-level standard: 29.92 inHg. Mountain pass at 3000 m: ~21 inHg. US aviation QNH given in inHg.

Read full inch of mercury reference →

Pound per Square Inch

psi

Pounds per square inch equals approximately 6895 Pa. It is the dominant pressure unit in the US — tyre pressures, plumbing, compressed air. Standard US tyre pressure: 32–35 psi.

Real-world: US tyre: 32–35 psi. Water supply: 40–60 psi. SCUBA tank: 3000 psi. Car AC system: 30–200 psi.

Read full pound per square inch reference →

Inch of Mercury to Pound per Square Inch conversion table

Common inches of mercury to psi values for quick reference.

Inch of Mercury (inHg)	Pound per Square Inch (psi)
1 inHg	0.4912 psi
5 inHg	2.45577 psi
10 inHg	4.91154 psi
25 inHg	12.2789 psi
50 inHg	24.5577 psi
100 inHg	49.1154 psi
200 inHg	98.2308 psi
500 inHg	245.577 psi
1,000 inHg	491.154 psi
5,000 inHg	2,455.77 psi

Tips & common mistakes

Quick tips

1 inHg ≈ 3386 Pa ≈ 33.86 mbar.
29.92 inHg = 1013.25 mbar = 1 atm.
US pilots use inHg; European pilots use hPa (mbar).

Avoid these

Confusing inHg with mmHg — factor of 25.4.
Mixing US and European altimeter units on a single flight plan.
Using inHg on scientific papers — prefer Pa.

Frequently asked questions

How many psi in a inch of mercury?

One inch of mercury equals 0.4912 psi.

How do I convert inches of mercury to psi?

Multiply the inch of mercury value by 0.4912 to get the equivalent in psi.

What is 100 inches of mercury in psi?

100 inches of mercury equals 49.1154 psi.

Is a inch of mercury bigger than a pound per square inch?

No. 1 inch of mercury equals 0.4912 psi, so one inch of mercury is smaller.

How to convert inches of mercury to psi without a calculator?

Multiply by 0.49 for a quick estimate; use a calculator for precise results.

Related pressure conversions

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