Pressure Converter: Pa, kPa, bar, atm, mmHg, Torr, psi and inHg
Scientific conversion tool across 14 pressure units, grouped by family: SI (Pa, hPa, kPa, MPa), bar and mbar, atmospheric/vacuum (atm, Torr, mmHg, inHg), engineering (psi, kgf/cm²) and water column (cmH₂O, mH₂O). Includes absolute mode and gauge mode, with the complementary equivalent always in view.
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When to use this tool
Quick conversion across units in physics, chemistry, geosciences and biology: gas laws (atm, bar, Pa, mmHg), hydrostatics and fluids (bar, kPa, mH₂O), barometric pressure and meteorology (hPa, mbar, inHg), pneumatics and engineering (psi, kgf/cm², bar) and clinical readings such as blood pressure (mmHg). Gauge mode solves the classic engineering need of turning a manometer (gauge) reading into absolute pressure and back.
How it works
Type a value, pick the source and target units: the result and the applied formula update instantly. The ⇄ button swaps source and target, and the 'Show all equivalents' panel lists the same value across all 14 units at once. Choose the kind of pressure with the Absolute / Gauge selector: absolute pressure is measured from a perfect vacuum, while gauge pressure is measured relative to the local atmospheric pressure (what an ordinary gauge reads). The converter always shows the complementary equivalent —for example, a 32 psi gauge reading next to its 46.70 psi absolute— and warns you if an absolute pressure would fall below vacuum. In gauge mode you can adjust the local atmospheric pressure (default 1 atm, or 1 bar for the 'barg' convention), useful at high altitude where the atmosphere differs from sea level. A precision detail: mmHg and Torr are treated as distinct units (1 atm = 760 Torr exactly, but 759.99988 mmHg), something most converters overlook.