Pressure Calculator
Convert pressure between pascals, hectopascals, kilopascals, megapascals, bar, atmospheres, kgf/cm², Torr, mmHg, inHg, psi and water columns. Edit any unit and the rest follow. Weather (hPa, inHg), tires (psi, kPa, bar), blood pressure (mmHg) and engineering (MPa, kgf/cm²) all in one table.
What does the Pressure Calculator do?
It converts a pressure into 17 units: SI pascals and their multiples, bar and millibar, standard and technical atmospheres, Torr and millimetres or inches of mercury, pounds per square inch, and millimetres, centimetres or inches of water. Type in whichever unit you have and read the rest; nothing leaves your browser.
How to use
- Type a value in a row, e.g. 32 in Pound per square inch. The other rows show ≈ 220.632 kPa and ≈ 2.20632 bar.
- Set rounding digits for the number of decimals displayed.
- Turn on Description to see each unit's definition, Ratio to see how it relates to the top row, and Separators for thousands separators.
- Drag the handle at the left of a row to reorder units; the top row is the (base unit).
- Press Up / Down in a row to add or subtract 1 of that unit.
Units and definitions
| Unit | Symbol | Definition |
|---|---|---|
| Pascal | Pa | 1 N/m² (SI unit) |
| Hectopascal / Kilopascal / Megapascal / Gigapascal | hPa / kPa / MPa / GPa | 100 / 1,000 / 10⁶ / 10⁹ Pa |
| Bar / Millibar | bar / mbar | 100,000 Pa / 100 Pa |
| Standard atmosphere | atm | 101,325 Pa |
| Technical atmosphere | at (kgf/cm²) | 98,066.5 Pa |
| Torr | Torr | 1/760 atm ≈ 133.322 Pa |
| Millimetre of mercury | mmHg | 133.322387415 Pa |
| Inch of mercury | inHg | 25.4 mmHg ≈ 3,386.39 Pa |
| Pound per square inch | psi | 1 lbf/in² ≈ 6,894.76 Pa |
| Kilopound per square inch | ksi | 1,000 psi |
| Millimetre / centimetre of water | mmH₂O / cmH₂O | 9.80665 Pa / 98.0665 Pa |
| Inch of water | inH₂O | 249.08891 Pa |
Conversion examples
- 1 atm = 1,013.25 hPa ≈ 14.6959 psi = 760 Torr
- 1 bar = 100 kPa ≈ 14.5038 psi
- 1 psi ≈ 6.89476 kPa
- 1 kgf/cm² = 0.980665 bar
- 29.92 inHg ≈ 1,013.2 hPa
Features
- 17 pressure units for weather, tires, medicine, diving and engineering
- Edit any row to convert in both directions
- Factors evaluated with 40-digit decimal arithmetic
- Rounding control, thousands separators, ratios and descriptions
- Unit order, value and options are remembered locally
FAQ
Are Torr and mmHg the same?
Almost. 1 Torr is defined as 1/760 atm (≈ 133.3224 Pa), while the conventional millimetre of mercury is 133.322387415 Pa. They differ by less than one part in 7 million.
Is this gauge or absolute pressure?
The units do not distinguish them. Tire gauges show gauge pressure (above atmospheric); add about 1 atm (101.325 kPa, 14.7 psi) to get absolute pressure.