// conversions › 2 · Mechanics & Fluids
Convert pressure between Pa, bar, PSI, atm, mmHg/Torr and inH₂O via the pascal.
result = value × (from→Pa) ÷ (to→Pa)
It converts convert pressure between pa, bar, psi, atm, mmhg/torr and inh₂o via the pascal by first normalising your value to the SI base unit (pascal) and then scaling to your chosen target unit. This hub-and-spoke approach guarantees every unit pair is internally consistent.
1 atm to PSI: 1 × 101325 = 101325 Pa, then ÷ 6894.757 ≈ 14.696 PSI.
One standard atmosphere is defined as exactly 101,325 Pa — the average sea-level air pressure. You can check it physically: a 760 mm column of mercury gives ρgh = 13,595 × 9.80665 × 0.76 ≈ 101,325 Pa, which is why a barometer reads 760 mmHg at sea level.
Tyre inflation, weather, hydraulics, diving and process engineering.
Conversions are exact ratios where the units are defined exactly (most SI and imperial units) and best-available constants otherwise. Extremely large or small magnitudes are shown in general (g) format; round-tripping through the base unit may introduce tiny floating-point differences in the final decimal places.