Pressure Converter
Convert between Pascals, kilopascals, bar, psi, atmospheres, mmHg and more instantly. Covers tyre pressures, weather, engineering and scientific applications.
| Pressure | Pa | bar | psi | atm |
|---|---|---|---|---|
| Standard atmosphere | 101,325 | 1.01325 | 14.696 | 1 |
| Car tyre (typical, 30 psi) | 206,843 | 2.069 | 30 | 2.041 |
| Bicycle tyre (80 psi) | 551,581 | 5.516 | 80 | 5.443 |
| 1 bar | 100,000 | 1 | 14.504 | 0.9869 |
| Deep sea (1,000 m) | 10,132,500 | 101.33 | 1,469.6 | 100 |
Common Pressure Conversion Questions
What is standard atmospheric pressure in different units?
Standard atmospheric pressure (1 atm) = 101,325 Pa = 101.325 kPa = 1.01325 bar = 14.696 psi = 760 mmHg. This is the sea-level pressure reference used across science, engineering and aviation.
How do you convert psi to bar?
1 psi = 0.0689476 bar. Multiply psi by 0.0689 to get bar. Going the other way: 1 bar = 14.5038 psi. So 30 psi (a typical UK car tyre front pressure) = 2.07 bar. Both units appear on UK garage air lines.
What tyre pressure should my UK car run at?
Most UK passenger cars run at 28–36 PSI (1.9–2.5 bar) for standard driving. Check the sticker inside the driver's door jamb or your handbook — pressures differ for front/rear and for loaded journeys. Always check when tyres are cold.
What unit does the UK Met Office use for weather pressure?
The UK Met Office uses millibars (mbar) and hectopascals (hPa) — they are identical (1 mbar = 1 hPa = 100 Pa). Standard sea-level pressure is 1,013.25 mbar. Low pressure (below ~1,000 mbar) typically brings unsettled weather; high pressure (above ~1,020 mbar) brings settled conditions.
What is the difference between gauge pressure and absolute pressure?
Absolute pressure is measured relative to a perfect vacuum. Gauge pressure (psig, barg) is measured relative to atmospheric pressure. Tyre pressures are gauge pressures — 2.0 bar gauge means 2.0 bar above atmospheric, or ~3.01 bar absolute.