Convert psi to millimeters of mercury

1 psi=51.7149mmHg

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

You have

Equals

51.71493

Conversion formula

Forward

millimeters of mercury = psi × 51.7149

Reverse

psi = millimeters of mercury × 0.01934

Example: 10 psi × 51.7149 = 517.149 mmHg.

About both units

From

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 →

Millimeter of Mercury

mmHg

The millimetre of mercury equals about 133.3 Pa — the pressure exerted by a 1 mm column of mercury at 0 °C under standard gravity. Traditionally and still used in medicine: blood pressure of 120/80 mmHg.

Real-world: Normal blood pressure: 120/80 mmHg. Atmospheric: 760 mmHg. Good vacuum: <1 mmHg.

Read full millimeter of mercury reference →

Pound per Square Inch to Millimeter of Mercury conversion table

Common psi to millimeters of mercury values for quick reference.

Pound per Square Inch (psi)	Millimeter of Mercury (mmHg)
1 psi	51.7149 mmHg
5 psi	258.575 mmHg
10 psi	517.149 mmHg
25 psi	1,292.87 mmHg
50 psi	2,585.75 mmHg
100 psi	5,171.49 mmHg
200 psi	10,342.99 mmHg
500 psi	25,857.46 mmHg
1,000 psi	51,714.93 mmHg
5,000 psi	258,574.63 mmHg

Tips & common mistakes

Quick tips

1 psi ≈ 6.9 kPa = 0.069 bar.
14.7 psi = 1 atm = 1.01 bar.
Most US pressure gauges show psi.

Avoid these

Setting a European tyre at 35 bar instead of 35 psi — disaster.
Confusing psi (gauge) with psia (absolute).
Using psi in scientific papers — prefer Pa or MPa.

Frequently asked questions

How many millimeters of mercury in a pound per square inch?

One pound per square inch equals 51.7149 millimeters of mercury.

How do I convert psi to millimeters of mercury?

Multiply the pound per square inch value by 51.7149 to get the equivalent in millimeters of mercury.

What is 100 psi in millimeters of mercury?

100 psi equals 5,171.49 millimeters of mercury.

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

Yes. 1 pound per square inch equals 51.7149 millimeters of mercury, so one pound per square inch is larger.

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

Multiply by 51.71 for a quick estimate; use a calculator for precise results.

Related pressure conversions

📊 See full comparison matrix →

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