About the Pressure Converter
This converts a pressure between the common units — pascals and kilopascals, bar, PSI, atmospheres, and millimetres of mercury. It's handy for tyre pressures (PSI vs bar vs kPa), weather pressure readings, diving and gas figures, or engineering and lab values. Choose the units and enter a value for an instant result.
How it works
Every unit is defined relative to the pascal (Pa), the SI unit; your value converts to pascals and then to the target unit. Key reference points:
- 1 bar = 100,000 Pa = 100 kPa.
- 1 PSI = 6894.76 Pa (pounds per square inch).
- 1 atmosphere (atm) = 101,325 Pa ≈ 1.013 bar ≈ 14.696 PSI — roughly average sea-level air pressure.
- 1 mmHg ≈ 133.322 Pa (millimetres of mercury), close to 1 torr.
So a car tyre at 32 PSI is about 2.2 bar or 221 kPa.
Assumptions and behaviour
- Uses the standard atmosphere (101,325 Pa) for the atm unit.
- mmHg and torr are nearly identical but defined slightly differently; both are included.
- Results show about 7 significant figures.
- The Swap button reverses the two units.
Limitations
- Gauge vs absolute pressure: this converts the number between units. It doesn't know whether your reading is gauge pressure (relative to atmosphere, like a tyre gauge) or absolute pressure — that distinction is up to you, and a tyre gauge reads gauge pressure.
- It converts pressure values; it doesn't compute pressure from force and area.
- Displayed values are rounded, so hand-chaining rounded figures can drift slightly.
Privacy
The conversion runs entirely in your browser. Nothing is uploaded or stored.
Get FreeMyTask as an app