Pressure Converter Free Online
Convert between pressure units instantly. Supports pascal, kilopascal, megapascal, bar, millibar, psi, atmosphere, mmHg, Torr, and inHg. Useful for engineering, weather (barometric), tire pressure, blood pressure, and vacuum work.
All Conversions
Pro — bulk batch conversion, API access, history & favorites
API access · Priority queue · Team workspace
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How It Works
Enter a Value
Type the number you want to convert into the From input. The conversion runs as you type — no Convert button needed. Decimals and very small or very large numbers are supported via scientific notation.
Pick Source & Target Units
Use the two dropdowns to choose source (From) and destination (To) units. The result updates automatically. Use the swap button to flip the conversion direction in one click.
See All Conversions
Below the main result, the All Conversions panel shows your input value converted into every supported unit at once — perfect for comparing metric vs imperial side by side.
Pressure Converter Features
SI Units
Pascal, kilopascal, megapascal, bar, millibar. The pascal is the SI base unit (1 Pa = 1 N/m²). Bar (10⁵ Pa) is the practical engineering unit.
US Customary
PSI = pounds per square inch. Standard for tire pressure, plumbing, and pressure vessels in the US. 1 psi ≈ 6.895 kPa.
Atmospheric
Atmosphere, bar, mbar, inHg. 1 atm = 101,325 Pa = 1013.25 mbar = 760 mmHg = 14.696 psi (standard sea-level pressure).
Medical / Vacuum
mmHg and Torr are nearly identical (1 Torr = 1/760 atm). Used for blood pressure (e.g. 120/80 mmHg) and vacuum work.
Live Conversion
Result updates as you type. Quickly check tire psi → bar before a drive abroad, or weather mbar → inHg.
100% Private
All math runs in your browser. Safe for industrial, medical, or scientific pressure data.
Free vs Pro
| Feature | Free | Pro |
|---|---|---|
| All 10 pressure units | ||
| Live conversion | ||
| All-units result table | ||
| Bulk CSV / Excel conversion | — | |
| REST API access | — | |
| Custom precision settings | — |
Frequently Asked Questions
Almost. 1 Torr is exactly 1/760 atm = 133.3224 Pa. 1 mmHg uses standard mercury density and gravity = 133.3223874 Pa. The difference is about 1 part in 7 million — negligible for any practical use.
Standard atmospheric pressure at sea level is 1 atm = 101,325 Pa = 1013.25 mbar = 760 mmHg = 14.696 psi = 29.92 inHg. It varies ±5% with weather and altitude.
Divide psi by 14.5038 to get bar. Example: 32 psi ÷ 14.5038 = 2.21 bar. Most European cars list tire pressure in bar; US lists psi.
Absolute pressure includes atmospheric pressure (so vacuum = 0). Gauge pressure (psig, barg) is measured relative to atmosphere (so a flat tire reads 0 psig but is at ~14.7 psi absolute). This converter does pure unit conversion — handle the atmospheric offset yourself if needed.
Systolic 120 mmHg = 16.0 kPa, diastolic 80 mmHg = 10.7 kPa. Most countries report blood pressure in mmHg; SI-strict literature uses kPa.