When you need this conversion
European tire placards, pressure washers, espresso machines (9 bar), boilers and water systems, and dive equipment.
Quick reference
- 1 bar = 14.5038 psi
- 2 bar = 29.0075 psi
- 2.2 bar = 31.9083 psi
- 2.5 bar = 36.2594 psi
- 3 bar = 43.5113 psi
- 10 bar = 145.038 psi
Home pressures
- Mains water: often 2–4 bar (29–58 psi).
- Combi boiler: 1–1.5 bar (14.5–21.8 psi) when cold.
- Espresso: 9 bar (130.5 psi) at the group head.
Common mistakes
Multiplying by 14.7. That’s the psi value of one atmosphere, not one bar. It overstates by 1.3%.
Reading millibar as bar. Weather maps use mbar or hPa: 1,013 mbar is 1.013 bar.
For the reverse, use psi to bar. For kilopascals, see psi to kPa.