Pressure Converter

How Pressure Converter works

Convert pressure between pascals, kilopascals, bar, psi, atmospheres and millimetres of mercury. Everything happens inside this page: the tool reads your input, runs the calculation or conversion locally, and hands the result back to you. Nothing is transmitted, because there is no backend to transmit it to.

That design choice is deliberate. Most free tool sites upload your files to a server, process them there, and quietly keep a copy. Toolcin cannot do that — the site is a set of static files. If your connection dropped the moment the page finished loading, every tool would still work.

Pascals at the bottom of everything

Every pressure unit reduces to pascals: 1 kPa is 1,000 Pa, 1 bar is 100,000 Pa, 1 psi is 6,894.757 Pa, 1 atm is 101,325 Pa and 1 mmHg is 133.322 Pa.

Because the base is small, switching between units moves the decimal point a long way — 1 bar is 100,000 Pa and 14.5 psi. That is why pressure gauges are scaled per industry rather than converted on the fly.

Gauge, absolute and the missing atmosphere

A tyre gauge reads gauge pressure — above ambient. A barometer reads absolute. The two differ by about 101.3 kPa, which is a huge relative error at low pressures.

Specifications usually say psig or psia, but not always. If a number looks off by roughly one atmosphere, this is why.

Where each unit lives

psi dominates in the US for tyres and hydraulics. Bar is standard across Europe for the same jobs. mmHg survives in medicine and vacuum work. Atmospheres appear in chemistry and in diving, where depth is converted to pressure.

Good to know

• Works offline once loaded, including on flights and in locked-down networks.
• No file size limit beyond your device's own memory.
• Free to use, with no account and no usage counter.
• Results are produced locally, so they are not logged or shared with anyone.

Questions