About the Pressure Converter
Pressure is force per unit area, and it shows up everywhere: tire inflation (PSI, bar), weather forecasts (millibars, hectopascals, inHg), blood-pressure readings (mmHg), scuba diving (atm or bar), industrial steam (kPa, MPa), and aerospace work. This tool converts between all the common pressure units so a number from a German engineering datasheet, an American tire shop, a French weather report, and a Japanese vacuum-pump spec sheet can all be compared on the same scale.
How to use it
- Pick the unit your value is in (Pa, kPa, MPa, bar, PSI, atm, mmHg, inHg).
- Pick the target unit.
- Type the pressure value — the converter applies the correct factor immediately.
- Swap source and target with the swap button to flip the conversion direction.
Common pressure conversions
| 1 atm (standard atmosphere) | 101.325 kPa ≈ 14.7 PSI ≈ 1.013 bar |
| 1 bar | 100 kPa ≈ 14.504 PSI |
| 1 PSI | 6.895 kPa ≈ 0.0689 bar |
| Car tire (typical) | 32 PSI ≈ 2.2 bar |
| Bicycle road tire | 100 PSI ≈ 6.9 bar |
| Sea-level atmospheric | 1013 hPa ≈ 29.92 inHg |
| Blood pressure (typical) | 120 mmHg ≈ 16 kPa |
| Espresso brewing | 9 bar ≈ 130 PSI |
Frequently asked questions
- Is PSI the same as PSI gauge?
- Not quite. 'PSIA' is absolute pressure (relative to a vacuum). 'PSIG' is gauge pressure (relative to local atmospheric pressure). Tire pressure is gauge — a flat tire reads 0 PSIG even though there's still ~14.7 PSI of air inside it. This converter works in absolute units; if you have a gauge reading, add ~14.7 PSI (or 1.013 bar) to get the absolute value.
- Why is atmospheric pressure measured in so many different units?
- Each unit comes from a different field. Meteorologists historically used inches of mercury (inHg) because barometers were mercury-based; modern weather services use millibars or hectopascals. Aviation uses inHg for altimeters. Engineers use PSI, bar, or kPa depending on country. Doctors stuck with mmHg for blood pressure for over a century because sphygmomanometers were mercury columns.
- What's the right pressure for my car tires?
- Whatever your vehicle's door-jamb sticker or owner's manual says — not the maximum number printed on the tire sidewall. The sidewall number is a safety limit; the recommended pressure is tuned to your specific car's weight and suspension.
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