Engineering Unit Converter

Different vendors, standards, and regions quote the same quantity in different units. This converter covers the handful that come up daily in process and instrumentation work: pressure, temperature, volume, flow, and power. Choose a category, type a value, and all related conversions update at once.

The Formula

Conversions are done by scaling to a base unit and back. The exact factors used:

Worked example. 100 psi in kPa is 100 × 6.894757 = 689.48 kPa. In inH2O it is 100 × 27.7076 = 2,770.76 inH2O. And 100 psi expressed in bar is 100 / 14.503774 = 6.895 bar.

The inches-of-water figure uses the 60 degF (gas industry) convention; a different reference temperature gives a slightly different inH2O factor. The standard-cubic-foot conversion here is a volume factor only; standard-conditions definitions (temperature and pressure basis) differ between standards, so scf-to-mass and scf-between-standards conversions are out of scope.

Assumptions and Limits

• Pressure conversions treat all values on the same basis (gauge or absolute). The tool does not add or remove atmospheric pressure; convert gauge-to-absolute separately.
• The inH2O factor uses the 60 degF convention stated above. Water column standards at 4 degF, 20 degF, or 68 degF differ by a fraction of a percent.
• The scf conversion is a pure volume ratio. Because "standard conditions" vary by standard, do not use it to compare gas volumes reported under different bases without matching the conditions first.
• Results are engineering estimates for quick conversion. For custody or billing, use the exact factors and conditions required by the governing standard.

FAQ