Pressure Unit Converter
Convert industrial pressure units including bar, psi, kPa, MPa, mbar, kgf/cm², mmHg, inHg, mmH₂O, inH₂O and atmosphere.
How to use this calculator
- 1
Enter the pressure value.
- 2
Select the source pressure unit.
- 3
Select the required destination unit.
- 4
Calculate and use the converted value.
Pressure specifications in instrumentation, pumps, hydraulic systems, tanks and process plants are commonly expressed in bar, psi, kPa, MPa, mbar or water-column units. This converter lets engineers move between those units without manually applying conversion factors.
Water-column units such as mmH₂O and inH₂O are especially common in low differential-pressure and hydrostatic-level work. For precise custody, laboratory or standards work, use the applicable reference conditions and standards.
Formula and assumptions
Conversion factors are referenced to the pascal. Water-column values use conventional standard-gravity factors.
Examples and guidance
- 1 bar equals 100 kPa.
- 1 psi is approximately 6.894757 kPa.
Continue your calculation
Move between related pressure, level, flow, signal and measurement calculations without starting a new search.
Questions and answers
Which pressure unit is the SI unit?
The pascal (Pa), equal to one newton per square metre, is the SI unit of pressure.
Why can water-column conversions vary?
Water density changes with temperature. This converter uses conventional factors based on standard gravity for practical engineering conversion.
Can I convert negative pressure values?
Yes. Negative gauge or differential values can be converted between the supported units.