maratoolHow to convert PSI to bar, kPa, and atm
Type a pressure in any unit — read psi, bar, kPa, atm, torr, or mmHg instantly.
Tire gauges read psi, European specs read bar, weather reports read hPa, and vacuum systems read torr. The Pressure Converter converts between all of them through the SI pascal.
How it works
- Pick units — "PSI (lbf/in²)" to "Bar (bar)", or any other pair.
- Type a value — the result updates as you type, with swap and copy.
- Copy — one click, with "Copied!" feedback.
Pressure conversion factors
Every unit converts through the pascal (the base unit). To convert A → B, multiply by A's factor and divide by B's:
| Unit | = this many pascals |
|---|---|
| Pascal (Pa) | 1 |
| Kilopascal (kPa) | 1,000 |
| Megapascal (MPa) | 1,000,000 |
| Bar (bar) | 100,000 |
| Millibar (mbar) | 100 |
| PSI (lbf/in²) | 6,894.757293168 |
| Atmosphere (atm) | 101,325 |
| Torr (Torr) | 133.322368421 |
| Millimeter of mercury (mmHg) | 133.322387415 |
| Inch of mercury (inHg) | 3,386.389 |
| Kilogram-force per cm² (kgf/cm²) | 98,066.5 |
When you need it
Everyday anchors: 1 bar ≈ 14.5 psi ≈ 100 kPa ≈ 0.987 atm. Car tires run around 2.0–2.5 bar (29–36 psi); standard atmosphere is exactly 101,325 Pa. Medical blood-pressure readings stay in mmHg by convention.
Sources & methodology
Conversion factors follow NIST Special Publication 811; exact-by-definition factors are marked in the tool itself. All math runs client-side in your browser — nothing is uploaded.
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