🌡️ Pressure Converter

Convert a pressure value between pascals, kilopascals, bar, PSI, atmospheres and millimeters of mercury.

Value

From Unit

All six units in pascals

A pascal is one newton per square metre. It is a tiny unit, which is why every practical pressure unit is a large multiple of it:

1 kPa  = 1,000 Pa
1 bar  = 100,000 Pa    = 100 kPa
1 psi  = 6,894.757293 Pa
1 atm  = 101,325 Pa    = 1.01325 bar = 14.6959 psi
1 mmHg = 133.322387 Pa (also called a torr)

The one worth carrying: 1 bar is 14.5038 psi. So 32 psi of tyre pressure is 32 × 6,894.757 = 220,632 Pa, which is 2.21 bar or 220.6 kPa.

Tyre pressures in all three units

PSI	Bar	kPa
28	1.93	193.1
30	2.07	206.8
32	2.21	220.6
35	2.41	241.3
40	2.76	275.8
50	3.45	344.7

Blood pressure keeps mmHg: 120 mmHg is 16.0 kPa. Weather forecasts use hectopascals, and a hectopascal is exactly one millibar, so 1013 hPa and 1013 mbar are the same reading.

Tyre and tank gauges show gauge pressure, measured against the air around them, while atm and Pa figures in physics are usually absolute. To turn a gauge reading into absolute pressure, add one atmosphere: a 32 psi tyre holds about 46.7 psi absolute.

Frequently asked questions

How many bar is 32 psi?

2.21 bar, or 220.6 kPa. One bar is 14.5038 psi, so dividing a psi figure by 14.5 is close enough for setting tyres by a forecourt gauge.

Is 1 bar the same as 1 atmosphere?

Nearly, but not exactly. One atmosphere is 101,325 Pa and one bar is 100,000 Pa, so a bar is 0.98692 atm. The bar was defined as a round number of pascals; the atmosphere was defined from sea level air pressure.

What is 120 mmHg in kPa?

16.0 kPa, and 2.32 psi. Blood pressure is still quoted in millimetres of mercury because it was originally read off a mercury column, where 120 mm of the liquid was the height the pressure supported.