🌡️ Pressure Converter
By ToolNimba Editorial Team · Updated 2026-06-19
Type in any box and every other unit updates instantly.
This pressure converter changes a value between pascals, kilopascals, bar, psi, atmospheres and millimetres of mercury (mmHg, also called torr). Type a number into any field and the rest update at once. It runs entirely in your browser, so nothing you enter is ever uploaded or stored.
What is the Pressure Converter?
Pressure is force spread over an area, defined as force divided by area. The SI unit is the pascal (Pa), which is one newton per square metre. A pascal is a very small amount of pressure, so real-world figures are usually quoted in larger units: kilopascals (kPa) for weather and engineering, bar for industry, pounds per square inch (psi) for tyres and plumbing in the US, atmospheres (atm) for chemistry, and millimetres of mercury (mmHg) for blood pressure and barometers.
Converting between these units is just multiplication, because each unit is a fixed multiple of the pascal. This tool converts every value through pascals as a common base: it turns whatever you type into pascals, then divides by the factor for each target unit. That keeps the conversions consistent in every direction, so going from psi to bar gives the same factor as going from bar to psi, only inverted.
The factors used here are the standard ones: 1 bar is exactly 100,000 Pa, 1 psi is 6,894.757 Pa, 1 standard atmosphere is exactly 101,325 Pa, and 1 mmHg (torr) is 133.322 Pa. From these you can derive the everyday rules of thumb, such as roughly 14.5 psi to a bar, or about 14.7 psi to one atmosphere of air pressure at sea level.
When to use it
- Converting a tyre pressure given in psi to bar for a European pump or manual.
- Switching a weather barometer reading between mmHg, inHg-adjacent units and kPa.
- Translating a lab or HVAC spec from pascals or kPa into psi for US equipment.
- Checking a scuba or compressor gauge reading in bar against a psi rating.
How to use the Pressure Converter
- Type the pressure you know into the matching field (for example, enter 30 in the psi box).
- Read the converted value from any of the other unit fields straight away.
- Enter a different value or switch fields at any time to convert in the other direction.
- Press Clear to reset every field and start a new conversion.
Formula & method
Worked examples
Convert a 30 psi tyre pressure to bar.
- pascals = 30 × 6894.757 = 206,842.71 Pa
- bar = 206,842.71 ÷ 100,000
- bar = 2.0684
Result: 30 psi is about 2.07 bar
Convert 2 bar to psi.
- pascals = 2 × 100,000 = 200,000 Pa
- psi = 200,000 ÷ 6,894.757
- psi = 29.0075
Result: 2 bar is about 29.01 psi
Convert 1 atmosphere to mmHg.
- pascals = 1 × 101,325 = 101,325 Pa
- mmHg = 101,325 ÷ 133.322
- mmHg = 760.0
Result: 1 atm is 760 mmHg
Pressure unit conversion factors (relative to the pascal)
| Unit | Symbol | Value in pascals (Pa) |
|---|---|---|
| Pascal | Pa | 1 |
| Kilopascal | kPa | 1,000 |
| Bar | bar | 100,000 |
| Pound per square inch | psi | 6,894.757 |
| Atmosphere | atm | 101,325 |
| Millimetre of mercury | mmHg / torr | 133.322 |
Common pressure equivalents at a glance
| From | Equals |
|---|---|
| 1 bar | 14.5038 psi |
| 1 psi | 0.0689476 bar |
| 1 atm | 14.6959 psi |
| 1 atm | 1.01325 bar |
| 1 atm | 760 mmHg |
| 1 kPa | 0.145038 psi |
Common mistakes to avoid
- Confusing bar with atmospheres. They are close but not equal. 1 atm is 1.01325 bar, so treating them as the same adds a small error that matters in precise work.
- Mixing up gauge and absolute pressure. Tyre and tank gauges usually read gauge pressure (above the surrounding air), while atm and absolute readings include the air itself. This converter changes units only, not between gauge and absolute, so subtract or add atmospheric pressure yourself if you need to switch reference.
- Assuming psi and kPa are interchangeable numbers. They are not close: 1 psi is about 6.895 kPa. Reading a 100 kPa value as 100 psi overstates the pressure nearly sevenfold.
Glossary
- Pascal (Pa)
- The SI unit of pressure, equal to one newton of force per square metre of area.
- Bar
- A metric pressure unit equal to exactly 100,000 pascals, close to average sea-level air pressure.
- psi
- Pounds per square inch, a US customary pressure unit common for tyres, plumbing and gauges.
- Atmosphere (atm)
- A standard reference pressure of exactly 101,325 pascals, roughly the air pressure at sea level.
- mmHg (torr)
- Millimetres of mercury, the pressure that supports a 1 mm column of mercury, equal to 133.322 pascals.
Frequently asked questions
How do I convert psi to bar?
Multiply the psi value by 0.0689476 to get bar, or just type the psi figure into this converter. For example, 30 psi is about 2.07 bar.
How do I convert pascal to psi?
Divide the pascal value by 6,894.757 to get psi. So 100,000 Pa (1 bar) is about 14.5 psi. Enter the pascal value here and read the psi field.
How many psi are in 1 bar?
One bar equals 14.5038 psi. Bar is defined as exactly 100,000 pascals and psi as 6,894.757 pascals, so dividing gives 14.5038.
Is 1 atmosphere the same as 1 bar?
No, but they are close. One standard atmosphere is 101,325 pascals, which is 1.01325 bar, so an atmosphere is about 1.3% higher than a bar.
What is mmHg and how does it relate to torr?
mmHg (millimetres of mercury) is a pressure unit used for blood pressure and barometers. It is treated as identical to the torr, with 1 mmHg equal to 133.322 pascals.
Is my data sent anywhere when I use this converter?
No. All conversions run in your browser with plain JavaScript. Nothing you type is uploaded, logged or stored, so the tool works offline once the page has loaded.