Pressure Converter

This free online pressure conversion tool makes it easy to convert a pressure measurement into a wide range of commonly used scientific, industrial, and everyday pressure units. Whether you’re working with weather data, engineering calculations, tire pressure, or laboratory measurements, this calculator provides fast and reliable conversions.

With this pressure calculator, you can convert between Pascals, Hectopascals, Kilopascals, Megapascals, Bar, Millibar, Millimetres of Mercury, Inches of Mercury, Pounds per Square Inch, and Atmospheres. Simply enter a value into any of the input fields, and the calculator will instantly convert and display the equivalent pressure values across all other supported units, eliminating the need for manual calculations.

Enter pressure value

Pascal

Hectopascal

hPa

Kilopascal

kPa

Megapascal

MPa

Bar

bar

Millibar

mbar

Atmosphere

atm

Pounds per Square Inch

psi

Millimetres of Mercury

mmHg

Inches of Mercury

inHg

Decimal places

Calculated in your browser as you type. Very small results can show as 0 when rounded to few decimal places.

How to use it

The pressure conversion calculator is a handy webtool to use to convert from one pressure to another.

Enter a valueType a pressure into any one of the fields. Any number is accepted, including the ‘e’ exponent such as 1e5.
Read the resultsAll the other fields update automatically with the converted pressures.
Copy a valueClick the clipboard button beside any field to copy it.
Tidy the numbersUse Decimal places to round the results, or leave it on full precision.

Handy conversions

1 atmosphere

Is 101,325 Pa, 1.01325 bar, 14.696 psi and 760 mmHg.

1 bar

Is exactly 100 kPa, and about 14.5 psi, handy for tyre pressures.

1 hPa

Is exactly 1 mbar, the figure used in weather reports.

Pressure unit comparison table

Unit name	Symbol	Description	Equals in pascals
Pascal	Pa	Base unit of pressure in the SI system	`1 Pa`
Hectopascal	hPa	Commonly used in meteorology	`100 Pa`
Kilopascal	kPa	Used in engineering and tire pressure	`1,000 Pa`
Megapascal	MPa	Used for high-pressure industrial applications	`1,000,000 Pa`
Bar	bar	Metric unit used in engineering and weather	`100,000 Pa`
Millibar	mbar	Common in atmospheric pressure measurements	`100 Pa`
Millimetres of Mercury	mmHg	Used in medicine and science	`133.322 Pa`
Inches of Mercury	inHg	Used in aviation and meteorology	`3,386.39 Pa`
Pounds per Square Inch	psi	Common in mechanical and automotive use	`6,894.76 Pa`
Atmosphere	atm	Standard reference pressure at sea level	`101,325 Pa`

Helpful notes

Weather

Hectopascals and millibars are numerically equivalent and widely used in weather reporting.

Medicine

mmHg is standard in medical blood pressure measurements.

Engineering

psi is commonly used in tire and hydraulic pressure, and atmospheres are often a reference point in physics and chemistry.

Frequently asked questions

How many psi are in a bar?

One bar is about 14.5038 psi. To convert bar to psi multiply by 14.5038, and to convert psi to bar multiply by 0.0689476.

Are hectopascals and millibars the same?

Yes. One hectopascal equals exactly one millibar, which is why weather reports use either one for atmospheric pressure.

What is standard atmospheric pressure?

One standard atmosphere is 101,325 Pa, which is 1,013.25 hPa, about 14.696 psi and 760 mmHg.

Is mmHg the same as torr?

In practice yes. One torr is 1/760 of a standard atmosphere, which differs from the strict mmHg by less than one part in seven million. This tool uses that value, so one atmosphere is exactly 760 mmHg.

Can I type very large or very small numbers?

Yes. Any number is accepted, including scientific notation such as 1e5 or 2.5e-3.

Is anything sent to a server?

No. The conversion is calculated in your browser as you type.