Tyre gauges read psi or bar, weather maps use hectopascals, blood pressure uses millimetres of mercury and engineers quote megapascals. The pascal is one newton per square metre; every other pressure unit here is an exact multiple of it.
How to use the Pressure Converter
- Pick the unit you are starting from in the From menu and type your value.
- Pick the unit you want in the To menu. The heading changes to match – for example “Bar to Psi Converter”.
- The most common pressure units are shown below at the same time, so you can compare them at a glance.
- Type into any result to convert backwards, then use Copy results – the copied text starts with the heading for your chosen units.
Results update as you type. Everything is calculated in your browser.
How it works
Every pressure unit is defined by an exact factor relative to the pascal (the base unit). The calculator first turns the value you type into pascals, then turns that into the unit you picked in the “To” menu and into each of the common units below it. This two-step method means any unit can be converted to any other – 18 units are available in each menu – and you can type into any field, including a result, to work in the other direction. Changing a unit menu keeps the quantity the same and just re-expresses it, and the page heading and copied results follow your choice.
How to convert pressure units
- Choose the unit you have in the From menu and type the value, for example 1 bar.
- Choose the unit you want in the To menu, for example psi. The page heading changes to “Bar to Psi Converter”.
- The calculator multiplies by the pascal factor of the “from” unit and divides by the factor of the “to” unit: 1 bar × 100,000 ÷ 6,894.7573 = 14.503774 psi.
1 bar in common units
| Unit | Value |
|---|---|
| Psi (psi) | 14.503774 |
| Standard atmospheres (atm) | 0.98692327 |
| Pascals (Pa) | 100,000 |
| Kilopascals (kPa) | 100 |
| Megapascals (MPa) | 0.1 |
| Millimetres of mercury (mmHg) | 750.06158 |
| Inches of mercury (inHg) | 29.52998 |
| Torr (Torr) | 750.06168 |
| Inches of water (inH₂O) | 401.46308 |
Bar conversion table
| Bar | psi | atm | Pa | kPa |
|---|---|---|---|---|
| 0.5 | 7.2518869 | 0.49346163 | 50,000 | 50 |
| 1 | 14.503774 | 0.98692327 | 100,000 | 100 |
| 2 | 29.007548 | 1.9738465 | 200,000 | 200 |
| 2.5 | 36.259434 | 2.4673082 | 250,000 | 250 |
| 3 | 43.511321 | 2.9607698 | 300,000 | 300 |
| 5 | 72.518869 | 4.9346163 | 500,000 | 500 |
| 10 | 145.03774 | 9.8692327 | 1,000,000 | 1,000 |
| 100 | 1,450.3774 | 98.692327 | 10,000,000 | 10,000 |
What is a bar?
One bar is exactly 100,000 Pa, close to average atmospheric pressure. European tyre pressures, diving, espresso machines and industrial gauges use bar.
What is a pound per square inch?
Pounds per square inch is the pressure of one pound-force on one square inch, about 6,895 Pa. U.S. tyre gauges, compressors and hydraulic equipment read psi.
What is a standard atmosphere?
The standard atmosphere is exactly 101,325 Pa, the average air pressure at sea level. Chemistry problems and diving depth calculations often use atm.
Common mistakes to avoid
Mixing gauge pressure (psig, barg) with absolute pressure (psia, bara), treating bar and atm as identical, and confusing kgf/cm² with bar.
Formula
1 bar = 14.503774 psi1 bar = 0.98692327 atm1 bar = 100,000 Pa1 bar = 100 kPa1 bar = 0.1 MPaWorked example
Inputs — From: 1 bar.
Results — To = 14.50377377 psi; Standard atmospheres = 0.98692327 atm; Pascals = 100,000 Pa; Kilopascals = 100 kPa; Megapascals = 0.1 MPa; Millimetres of mercury = 750.06157585 mmHg; Inches of mercury = 29.52998016 inHg.
Frequently asked questions
How many psi is 1 bar?
About 14.5038 psi.
Is 1 atm the same as 1 bar?
No. 1 atm = 101,325 Pa, slightly more than 1 bar (100,000 Pa).
Are torr and mmHg the same?
Almost: 1 Torr = 1/760 atm, and 1 mmHg differs by less than 0.000015%.
How do I change the units?
Pick any unit in the From and To menus. The value is converted in place, and the heading changes to show your conversion, for example “Bar to Psi Converter”.
Can I type into any field?
Yes. Every field is editable, so you can start from whichever unit you have.
How many units can I convert between?
18 pressure units, from the everyday to the specialised.
Which units are exact?
All factors here are exact by definition except astronomical and similar reference values, which use internationally agreed constants.
What formula does the Pressure Converter use?
1 bar = 14.503774 psi.