Pressure Unit Converter
Convert pressure between pascals, kPa, bar, psi, atmospheres, mmHg and inHg with exact SI factors.
How it works
pascals = value × factor(from) · result = pascals ÷ factor(to) (1 atm = 101325 Pa, 1 psi ≈ 6894.76 Pa)
Pressure is force per unit area; the SI unit is the pascal (one newton per square metre). Everything else is a scaled pascal: a bar is exactly 100000 Pa, a standard atmosphere is 101325 Pa, and a psi is about 6894.76 Pa. Millimetres of mercury (torr) and inches of mercury come from barometer columns and are common in weather and medicine.
Worked example
Convert 1 atmosphere to psi: 1 × 101325 = 101325 Pa, then 101325 ÷ 6894.757 ≈ 14.70 psi. That is why sea-level pressure is often quoted as 14.7 psi.
Sources: Pressure — Wikipedia
Frequently asked questions
How many psi are in a bar?
One bar is 100000 Pa, and one psi is about 6894.76 Pa, so 1 bar ≈ 14.50 psi. Tyre pressures given in bar are therefore roughly 14.5 times the number in psi.
Is atmosphere the same as bar?
Nearly, but not exactly. A standard atmosphere is 101325 Pa (about 1.01325 bar), so 1 atm is slightly more than 1 bar. For rough work they are often treated as equal.
What is mmHg used for?
Millimetres of mercury (also called torr) measure the height of a mercury column and are standard for blood pressure and barometric readings. Normal sea-level pressure is about 760 mmHg.
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