CONVERSIONS

Convert between psi, kPa, bar, atm, mmHg, and more. Enter a value and pick the units.

Value

From

Converted

—

In the target unit.

Usage Tip

Tire anchors: 32 psi ≈ 2.2 bar ≈ 221 kPa. Weather: about 1013 hPa = 1 atm.

THE MATH

Convert to a base unit, then to the target:
result = value × (from factor ÷ to factor)

Pressure is force per area; it converts through pascals. Everyday contexts: tire pressure (psi or bar), weather (hPa, inHg), vacuum (torr, mmHg).
One standard atmosphere is 101,325 Pa.

1 atm ≈ 101.3 kPa ≈ 14.7 psi ≈ 760 mmHg ≈ 1.013 bar.
mmHg and torr are essentially identical.
Tire pressures are gauge pressure (above atmospheric), not absolute.

Practical Notes

Pressure is force per unit area, and there are many units for it. One atmosphere equals 101.325 kilopascals, 1.01325 bar, 14.696 psi, and 760 millimeters of mercury. One bar is exactly 100 kilopascals, and one psi is about 6.895 kilopascals.

Many gauges read gauge pressure, which is the pressure above the surrounding atmosphere, while some calculations need absolute pressure, which adds atmospheric pressure to the gauge reading. The conversion between units is the same for both, but make sure you know which one a figure refers to. Tire pressure is usually given in psi or bar, weather pressure in hectopascals or millibars, and blood pressure in millimeters of mercury.

Spotted an error or have a suggestion for this calculator? Let us know →