🌡️ Pressure Converter
Tire pressure in psi, weather in millibars, blood pressure in mmHg, SCUBA in atmospheres — pressure has more units than any other measurement.
Last updated — conversions use exact ISO unit definitions.
How it works
All pressure conversions route through the pascal (Pa = N/m²), the SI unit. One atmosphere (atm) at sea level = 101,325 Pa = 1.01325 bar = 14.696 psi. The bar (100,000 Pa ≈ 0.987 atm) is widely used in engineering because it's close to one atmosphere.
PSI (pounds per square inch) dominates in the US for tires, plumbing, and industrial pressure. mmHg (millimeters of mercury, also called torr after Torricelli) is used in medicine and vacuum systems — 1 atm = 760 mmHg = 760 torr.
Gauge pressure vs absolute pressure: tire gauges read gauge pressure (pressure above atmospheric). Absolute = gauge + 1 atm. 32 psi gauge ≈ 46.7 psi absolute ≈ 2.21 atm ≈ 224 kPa.
How pressure units relate
1 atm = 14.696 psi = 1.01325 bar = 101.325 kPa = 760 mmHg = 760 torr. Pressure is force per area. Bar = 100 kPa, almost one atmosphere.
How accurate are these conversions?
All conversions use ISO 80000 standard unit definitions. For example, 1 inch = 2.54 centimeters exactly by international agreement.
Why can't I see all units on mobile?
The result table scrolls horizontally. The headline pair above shows the most commonly requested conversion.
Do you store my inputs?
No. All calculations happen in your browser. We collect zero personal data.
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