Pressure Converter

A pressure converter for bar to psi and psi to bar, kPa to psi, atmospheres, mmHg, inHg and torr — every unit at once, with exact defined factors.

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Runs entirely in your browser. What you enter stays on your device — nothing is sent to a server. Verify it yourself

How many psi is 1 bar?

1 bar is about 14.504 psi, and 1 psi is about 0.0689 bar. Both are defined exactly — the bar as 100,000 pascals, the psi from the exact pound, inch and standard gravity — so the factor is fixed, not measured.

Cost: Free, no limits
Upload: None — runs on your device
Sign-up: Not required
Works offline: Yes, once loaded

How to convert bar to psi

Enter the value
Type the number into the Value box; the result updates as you type.
Choose the units
Pick From and To — bar and psi to begin with, or pascals, atmospheres, millimetres of mercury or kilograms-force per cm². The swap button between them flips the direction.
Read every unit at once
The All units table below the result shows the value in every pressure unit.

Examples

2.2 bar31.91 psi · 220 kPa
A typical car tyre pressure.
1013.25 hPa1 atm · 29.92 inHg
Standard air pressure at sea level.

Key features of the Pressure Converter

Converts between 12 pressure units
Converts as you type, in both directions
Metric and imperial in the same list
Runs entirely in your browser

Supported formats

Units

Pascals
Hectopascals
Kilopascals
Megapascals
Millibars
Bars
Pounds per square inch
Standard atmospheres
Torr
Millimetres of mercury
Inches of mercury
Kilograms-force per cm²

When should you use this?

Setting tyre pressures from a manual that uses the other unit.
Reading a weather chart or barometer in hectopascals or inches of mercury.
Converting diving cylinder or compressor ratings.
Checking engineering specifications in kPa or MPa.

Limitations

Conversions go through a base unit, so a value converted from one unit to another and back can differ in the last decimal place. That is floating-point arithmetic, not a defect, and it is far below the precision of any real measurement.
Results are displayed rounded for readability. If you need a specific number of significant figures, round the displayed value yourself rather than assuming the display is exact.
Converting a measurement cannot make it more precise than it was. A length measured to the nearest centimetre is still that precise after conversion, however many decimal places appear.
Gauge and absolute pressure have different zero points: a gauge reads zero at atmospheric pressure. The converter changes the unit, not the reference, so turn a "psia" figure into a gauge reading by subtracting about 14.7 psi.

Troubleshooting

The answer disagrees with another converter

Usually a different definition of the same unit name — US versus imperial, or a short versus a long ton. Check which variant each tool means before assuming one is wrong.

The last decimal place changes on a round trip

Conversion factors are not exact in binary floating point. The error is around one part in ten thousand billion, which no physical measurement can detect.

Common mistakes to avoid

Assuming a unit name is unambiguous. It very often is not.
Rounding partway through a multi-step calculation instead of at the end.
Comparing an absolute-pressure specification with a gauge reading without allowing for the atmosphere in between.

Pro tips

Tips for better results

US and UK units
The same unit name can mean two amounts
Check which system a unit belongs to before trusting it. Several unit names mean different amounts in the US and the UK.
Working method
Write the unit beside every number
Carry the unit through your working rather than converting at the end. Most unit errors happen when a number is written down without one.
Tyres
Use the door placard figure, not the number on the sidewall
For tyres, use the pressure on the placard inside the driver’s door, not the maximum moulded into the sidewall.

Standards and terms behind the Pressure Converter

The named things this tool works with, and the documents that define them.

SI unitsSpecification: The international system of units, maintained by the BIPM, which fixes the metre, kilogram, second and kelvin. Reference: SI units
Imperial and US customary unitsSpecification: Inches, feet, pounds, gallons and Fahrenheit — still standard in the United States and common in the UK.

Also searched as: psi to bar, tyre pressure conversion, kpa to psi.

Which unit you will meet where

psi — tyre pressures in the US and UK, compressors and pressure washers.
bar — tyre pressures in much of Europe, espresso machines and diving cylinders.
kPa — tyre placards in Canada, Australia and Japan, and engineering generally. 100 kPa is 1 bar.
hPa and mbar — the same size as each other. Weather forecasts quote air pressure in hectopascals, around 1013 at sea level.
mmHg — blood pressure and vacuum gauges.
inHg — barometers and aircraft altimeters in the US.
atm — chemistry, and the pressure of the air at sea level.

Gauge pressure and absolute pressure

A tyre gauge reads zero in the open air — it measures how far above atmospheric pressure the tyre is. That is gauge pressure (psig, barg). Absolute pressure counts from a perfect vacuum, so it is gauge pressure plus about 1.013 bar. The converter changes units, not the reference: a gauge reading converts to a gauge reading. When a specification says "psia" or "bar absolute", subtract atmospheric pressure before comparing it with your gauge.

Exact factors

The atmosphere is defined as exactly 101,325 Pa and the bar as exactly 100,000 Pa, so an atmosphere is 1.01325 bar. The psi follows from the exactly defined pound, inch and standard gravity: 6,894.757 Pa. The torr is exactly 1/760 of an atmosphere; the millimetre of mercury is defined from mercury's density and differs from the torr by less than one part in seven million — which is why both are listed, and why in practice nobody needs to care.

Privacy

The Pressure Converter runs entirely in your browser. What you enter and the result it produces stay on your own device — nothing is sent anywhere, because nothing needs to be.

You can confirm this rather than take our word for it: open your browser’s developer tools, watch the Network tab, and use the tool. No request carries your input. It also keeps working with the connection off.

Details are in the privacy policy.

What next?

Pressure and temperature go together in tyres, weather and gas calculations.

Convert temperatures

Pressure Converter — questions

How do I convert psi to kPa?

Multiply by 6.895: 32 psi is 220.6 kPa. For kPa to psi, multiply by 0.145 — 1 kPa is about 0.145 psi.

How do I convert bar to psi?

Multiply by 14.5038. A tyre at 2.2 bar is about 31.9 psi; 2.5 bar is about 36.3 psi.

What is normal atmospheric pressure?

Standard atmospheric pressure is 1013.25 hPa — 1.01325 bar, 14.696 psi or 760 mmHg. Real sea-level pressure moves around that with the weather, typically between about 980 and 1040 hPa.

Is a hectopascal the same as a millibar?

Yes. Both are 100 pascals, which is why weather services could switch from millibars to hectopascals without changing a single number on their charts.

Why does my tyre gauge read zero on a flat tyre?

Because it measures gauge pressure — the difference from the air around it. A flat tyre still holds air at atmospheric pressure, about 14.7 psi absolute, which the gauge treats as zero.

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