Pressure Converter

Tyre pressures are given in psi or bar, weather in hectopascals or millibars, blood pressure in mmHg, and engineering drawings in MPa or kgf/cm². This converter covers all the common pressure units with their standard definitions, from the pascal (one newton per square metre) to the standard atmosphere (exactly 101,325 Pa).

How to use Pressure Converter

1. Type the value you want to convert.
2. Choose the unit you have in From and the unit you want in To. The swap button turns the conversion round.
3. Read the answer, with the formula underneath. For example, 2.2 bar ≈ 31.9 psi, a common car tyre pressure.
4. Open All units to see the value in every unit at once, and copy the one you need.

When it comes in handy

• Converting tyre pressure between psi and bar.
• Reading weather maps and barometers in hPa, mbar or inHg.
• Engineering and hydraulics calculations.

Frequently asked questions

Is a hectopascal the same as a millibar?

Yes. 1 hPa = 1 mbar = 100 Pa, which is why weather services switched from millibars to hectopascals without changing the numbers.

What is the difference between gauge and absolute pressure?

Gauge pressure (psig) is measured above the surrounding air pressure; absolute pressure (psia) includes it. A tyre at 32 psi gauge is at about 46.7 psi absolute at sea level. The converter converts the number you give it and does not add or remove atmospheric pressure.