Pressure Converter
Convert pressure between pascals, kilopascals, bar, psi, atmospheres and mmHg. Covers tire pressures, weather reports, blood pressure units and engineering specs.
How to use this calculator
- Enter the pressure value.
- Choose the from and to units.
- Press Convert to see every unit at once.
Formula used
The pascal (1 N/m²) is the SI unit; a bar is exactly 100,000 Pa and conveniently close to one atmosphere. Psi (pounds per square inch) dominates in the US; mmHg persists in medicine for blood pressure.
Example calculation
A tire at 2.5 bar: 2.5 × 100,000 ÷ 6,894.76 = 36.26 psi. Standard atmospheric pressure is 1.013 bar = 14.7 psi = 760 mmHg.
Pressure units by field
Each field kept its favorite unit: tires use bar (Europe) or psi (US), meteorology uses hPa/millibars, medicine uses mmHg for blood pressure, diving uses bar or atmospheres, and engineering uses pascals.
Anchors: typical car tires run 2.2–2.5 bar (32–36 psi); sea-level air pressure is ~1,013 hPa; every 10 m of water depth adds about 1 bar.
Why use this calculator?
- Convert tire pressures between the bar and psi stamped on different gauges.
- Read weather (hPa), diving (bar/atm) and medical (mmHg) figures in familiar units.
- Exact factors for engineering calculations.
Frequently asked questions
How many psi is 1 bar?
14.5038 psi. Quick tire rule: bar × 14.5 = psi, so 2.4 bar ≈ 35 psi.
What is normal atmospheric pressure?
1 atmosphere = 101,325 Pa = 1.01325 bar = 14.696 psi = 760 mmHg at sea level. Weather maps show it as ~1013 hPa (hectopascals = millibars).
Why is blood pressure in mmHg?
Historical instruments measured how many millimeters of mercury the pressure could push up a column. "120/80" means 120 and 80 mmHg — about 0.16 and 0.11 bar.