Math

Pressure Converter

Convert between Pascal, kPa, bar, psi, atm, and more.

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THE NUMORIX GUIDE

How to use the Pressure Converter

Last reviewed September 14, 2026

What this calculator does

The converter normalizes the source value to pascals and divides by the destination factor.

Formula and method

The converter normalizes the source value to pascals and divides by the destination factor. It uses 1 kPa = 1,000 Pa, 1 MPa = 1e6 Pa, 1 bar = 100,000 Pa, 1 psi = 6,894.757 Pa, 1 atm = 101,325 Pa, 1 mmHg = 1 torr = 133.3224 Pa, and 1 inHg = 3,386.389 Pa.

Variables and inputs

Enter a numeric pressure and choose Pa, kPa, MPa, bar, psi, atm, mmHg, inHg, or torr. The interface displays every unit after conversion and uses up to eight significant digits. It does not ask whether the input is gauge or absolute pressure.

Worked example

For 1 atm, the engine computes 1 x 101,325 = 101,325 Pa, which is 101.325 kPa, 1.01325 bar, about 14.6959 psi, and approximately 760 mmHg or torr.

How to interpret the result

Pressure is force distributed over area, so the same pressure can be represented in several units. A unit conversion does not change the reference: gauge pressure remains gauge and absolute pressure remains absolute.

Common mistakes to avoid

Do not confuse gauge pressure with absolute pressure, and do not add atmospheric pressure merely because the result is shown in atm. Use force per square meter for pascals, distinguish mmHg from inHg, and avoid treating a pressure unit as a force unit.

Assumptions and limitations

The factors for psi, mmHg, inHg, and torr are fixed rounded or conventional values in the engine. The UI allows zero, negative, or nonphysical inputs and does not model altitude, fluid columns, temperature, calibration, pressure gradients, or a measurement reference.

Sources and references

COMMON QUESTIONS

Frequently asked questions

What is the difference between gauge and absolute pressure?

Absolute pressure is referenced to a vacuum. Gauge pressure is referenced to local atmospheric pressure. This converter changes units but does not convert one reference type into the other.

Is 1 atm exactly 101.325 kPa here?

Yes. The engine uses 1 atm = 101,325 Pa, which is 101.325 kPa. Other pressure references, such as a local barometric reading, need not equal standard atmosphere.

Are torr and mmHg interchangeable?

The engine assigns both 133.3224 Pa, so it treats them as numerically equal for this conversion. Historical definitions and high-precision work can distinguish the conventions, so retain the original label.