Pressure Converter

How pressure conversion works

Every pressure unit here converts through the Pascal (Pa) — the SI base unit of pressure, defined as one newton of force per square meter. Units like PSI, bar, and atmospheres were each defined independently by different industries and countries, which is why the conversion factors between them look so irregular rather than round numbers.

Common conversions

• 1 atmosphere ≈ 14.696 PSI ≈ 1.01325 bar ≈ 101,325 Pa
• 1 bar = 100,000 Pa = 100 kPa
• Standard car tire pressure is often around 30–35 PSI (about 2–2.4 bar)
• 1 Torr ≈ 1 mmHg, historically defined from mercury barometer readings

Factors and display

The tool passes through pascals, using 1,000 Pa per kPa, 100,000 per bar, 6,894.757293168361 per PSI, 101,325 per atmosphere, 133.322368421 per Torr and 3,386.389 per inch of mercury. Torr and mmHg are treated as the same unit. Results update as you type, show up to six decimals and follow your browser's digit grouping. The default converts 1 atm to PSI.

Worked examples

• 1 atm = 14.695949 PSI (the default).
• 32 PSI = 2.206322 bar = 220.632233 kPa. 35 PSI = 2.413165 bar.
• 2.5 bar = 36.259434 PSI, and 1 bar = 0.986923 atm.
• 760 Torr = exactly 1 atm, and 1013.25 kPa = 10 atm.
• 29.92 inHg = 101.320759 kPa.
• 1 Pa = 0.000145 PSI, so very small PSI values lose digits at six decimals.
• 14.7 PSI = 1.000276 atm, a little above 1 because one standard atmosphere is 14.695949 PSI.

Notes and limits

The tool converts the number you give it and does not distinguish gauge pressure from absolute pressure. A tire gauge reading in PSI converts as a plain value, with no atmosphere added. Altitude, temperature and vacuum scales are not handled, and negative values are converted as typed.

Further conversions

14.7 psi is 101.352932 kPa, which is close to one atmosphere, 5 kPa is 37.503084 torr, and 2 atm is 2.0265 bar. Torr and mmHg are treated as the same unit.

Because pressure is sometimes quoted as gauge, measured against the surrounding air, and sometimes as absolute, confirm which one a figure is before converting it. This tool changes the unit only and does not shift between the two.