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Pressure Converter: Convert PSI, Bar, Pascal, kPa, MPa, atm and Torr

Pressure measurements appear everywhere from car tires and weather reports to hydraulic systems, air compressors, engineering equipment, and scientific experiments. The problem is that pressure can be expressed in many different units. A tire gauge may show PSI, an engineering specification may use MPa, a weather report may use hPa or millibars, and a scientific calculation may use pascals.

The CalculatorKits Pressure Converter makes these conversions much easier. Enter the pressure value, choose the unit you have, select the unit you need, and the converted result appears instantly.

For example:

1 bar = 14.5038 PSI

and:

1 atmosphere = 101,325 pascals

The CalculatorKits tool supports 10 pressure units and uses the pascal (Pa) as its base unit. Calculations are performed in the browser without requiring registration.

Use the CalculatorKits Pressure Converter

What Is a Pressure Converter?

A pressure converter changes a pressure measurement from one unit into another while representing the same physical pressure.

Pressure describes force distributed over an area. The SI unit of pressure is the pascal (Pa), which is equal to one newton per square meter.

Common pressure units include:

1. Pascal, Pa
2. Kilopascal, kPa
3. Megapascal, MPa
4. Bar, bar
5. Pounds per square inch, PSI or psi
6. Standard atmosphere, atm
7. Torr
8. Millibar, mbar
9. Pounds per square foot, psf
10. Other specialized pressure units depending on the application

The pascal is the SI unit of pressure. The BIPM defines the pascal as a derived SI unit equal to a newton per square meter.

A pressure converter is useful because different industries have developed different conventions. PSI is familiar in the United States for tire and equipment pressure, bar is common in many industrial and automotive applications, pascals are standard in SI based technical work, and atmospheric pressure is often expressed in atm, kPa, hPa, or millibars.

How to Use the CalculatorKits Pressure Converter

The CalculatorKits tool uses a straightforward From and To workflow.

Step 1: Enter the pressure value

Open the Pressure Converter and enter the number you want to convert.

For example: 1

Step 2: Choose the original unit

Use the From selector to identify your starting pressure unit.

For example:

From: Bar

Step 3: Choose the target unit

Select the unit in which you want the result.

For example:

To: PSI

Step 4: Read the result

The converter immediately displays the equivalent pressure.

For example:

1 bar = 14.5038 PSI

You can then change the value or switch the units to perform another conversion.

The CalculatorKits converter also provides commonly used presets such as bar to PSI, PSI to bar, pascal to kilopascal, kilopascal to pascal, atmosphere to pascal, and torr to pascal.

What Are the Most Common Pressure Units?

Different pressure units are useful in different situations.

Pascal

The pascal, written as Pa, is the SI unit of pressure.

It is defined as:

1 Pa = 1 N/m²

Because one pascal is relatively small, larger pressures are commonly expressed using prefixes.

For example:

1 kPa = 1,000 Pa

1 MPa = 1,000,000 Pa

Pascals are widely used in science, engineering, fluid mechanics, meteorology, and technical specifications.

Kilopascal

The kilopascal, written as kPa, equals:

1 kPa = 1,000 Pa

It is commonly used for atmospheric pressure, tire pressure in some countries, building systems, and engineering calculations.

For example:

1 bar = 100 kPa

Megapascal

The megapascal, written as MPa, equals:

1 MPa = 1,000,000 Pa

It is particularly useful for higher pressures.

For example:

1 MPa = 10 bar

MPa is commonly encountered in hydraulic systems, material specifications, concrete strength, pressure vessels, and engineering.

Bar

The bar is a non-SI unit that is widely used for pressure.

Its relationship to the pascal is:

1 bar = 100,000 Pa

or:

1 bar = 100 kPa

The BIPM lists the bar as a non-SI unit with this exact relationship to the SI system.

Bar is commonly used for vehicle tires, compressors, industrial equipment, and pressure specifications.

PSI

PSI means pounds per square inch.

It is written as psi or PSI and describes pressure in terms of pounds-force applied over one square inch.

The conversion is approximately:

1 psi = 6,894.757 Pa

Therefore:

1 psi ≈ 0.0689476 bar

PSI is especially common in the United States for tire pressure, air compressors, hydraulic equipment, and other mechanical applications.

Atmosphere

The standard atmosphere, written as atm, is defined as:

1 atm = 101,325 Pa

It is approximately:

1 atm = 1.01325 bar

and:

1 atm ≈ 14.6959 psi

Atmospheric pressure is often used as a reference when discussing gases, weather, chemistry, diving, and physical science.

Torr

The torr is a pressure unit commonly encountered in vacuum science and laboratory applications.

Approximately:

1 Torr = 133.322 Pa

and:

760 Torr = 1 standard atmosphere

NIST provides conversion factors for pascals, torr, PSI, atmosphere, bar, and other pressure units.

Pressure Conversion Table

Here are some of the most useful pressure relationships.

Conversion	Equivalent
1 bar to pascals	100,000 Pa
1 bar to kPa	100 kPa
1 bar to MPa	0.1 MPa
1 bar to PSI	14.5038 psi
1 psi to pascals	6,894.757 Pa
1 psi to bar	0.0689476 bar
1 atm to pascals	101,325 Pa
1 atm to kPa	101.325 kPa
1 atm to bar	1.01325 bar
1 atm to PSI	14.6959 psi
1 Torr to pascals	133.322 Pa
1 MPa to bar	10 bar
1 MPa to PSI	145.038 psi
1 kPa to pascals	1,000 Pa

NIST’s pressure conversion tables provide corresponding relationships among pascals, millibars, torr, PSI, atmosphere, inches of water, and inches of mercury.

How Pressure Conversion Works

CalculatorKits uses the pascal as the base unit for its pressure calculations.

The general conversion method is:

Result = (Input × From Factor) ÷ To Factor

For example, consider converting:

1 bar to PSI

First convert the bar value to pascals:

1 × 100,000 = 100,000 Pa

Then convert pascals to PSI:

100,000 ÷ 6,894.757 ≈ 14.5038 PSI

Therefore:

1 bar = 14.5038 PSI

The converter performs these steps automatically.

This base unit approach makes it possible to convert between many pressure units consistently without manually calculating an intermediate value.

Bar to PSI

Bar to PSI is one of the most common pressure conversions.

The formula is:

PSI = Bar × 14.5038

For example:

2 bar × 14.5038 = 29.0076 PSI

Therefore:

2 bar ≈ 29.01 PSI

For:

5 bar

the result is:

72.519 PSI

So:

5 bar ≈ 72.52 PSI

PSI to Bar

To convert PSI to bar:

Bar = PSI × 0.0689476

For example:

30 PSI × 0.0689476 ≈ 2.06843 bar

Therefore:

30 PSI ≈ 2.07 bar

This conversion is particularly useful when a vehicle specification uses PSI but your tire gauge or compressor uses bar.

Bar to kPa

Because:

1 bar = 100 kPa

the conversion is very simple.

For example:

2.5 bar = 250 kPa

and:

10 bar = 1,000 kPa

This relationship is useful for switching between industrial specifications that use bar and technical documents that use kilopascals.

kPa to Bar

The reverse calculation is:

Bar = kPa ÷ 100

For example:

250 kPa ÷ 100 = 2.5 bar

Therefore:

250 kPa = 2.5 bar

MPa to Bar

The relationship is:

1 MPa = 10 bar

Therefore:

5 MPa = 50 bar

and:

10 MPa = 100 bar

MPa is especially useful for higher pressure applications where expressing the same value in pascals would require many digits.

PSI to kPa

To convert PSI to kilopascals:

kPa = PSI × 6.894757

For example:

32 PSI × 6.894757 ≈ 220.632 kPa

Therefore:

32 PSI ≈ 220.63 kPa

This is a useful conversion for automotive tire pressure.

kPa to PSI

For the reverse:

PSI = kPa × 0.145038

For example:

220 kPa × 0.145038 ≈ 31.9084 PSI

Therefore:

220 kPa ≈ 31.91 PSI

atm to kPa

Atmospheric pressure can be converted directly:

1 atm = 101.325 kPa

Therefore:

2 atm = 202.65 kPa

and:

0.5 atm = 50.6625 kPa

This conversion is common in chemistry, physics, atmospheric science, and gas calculations.

Torr to Pascal

The relationship is approximately:

1 Torr = 133.322 Pa

Therefore:

100 Torr ≈ 13,332.2 Pa

and:

760 Torr ≈ 101,325 Pa

The latter corresponds to one standard atmosphere.

NIST notes that some pressure units based on mercury columns have definitional and practical complexities, which is one reason it is useful to identify the exact unit and conversion factor being used.

Pressure in Car Tires

Tire pressure is one of the most familiar everyday uses of pressure conversion.

For example:

32 PSI ≈ 2.21 bar

and:

32 PSI ≈ 220.63 kPa

A tire specification may therefore display:

32 PSI

while another gauge may display:

2.2 bar

or:

220 kPa

These values describe approximately the same pressure.

Always follow the vehicle manufacturer’s recommended tire pressure rather than choosing a pressure based solely on a generic conversion.

Also note that tire pressure can change with temperature and operating conditions. The correct pressure should be checked according to the vehicle manufacturer’s instructions.

Atmospheric Pressure

At standard reference conditions:

1 atm = 101,325 Pa

which is:

101.325 kPa

and approximately:

1.01325 bar

or:

14.6959 PSI

This is a useful reference point when interpreting weather and scientific pressure measurements.

Weather services commonly use other units such as hectopascals or millibars. Since:

1 hPa = 1 mbar = 100 Pa

they are numerically equivalent units of pressure.

For example:

1,013.25 hPa = 101,325 Pa

which corresponds to one standard atmosphere.

Pressure in Air Compressors

Air compressors commonly display pressure in PSI or bar.

For example:

100 PSI ≈ 6.89476 bar

Therefore, a compressor rated at approximately 100 PSI is operating at roughly 6.9 bar.

Industrial specifications may instead use MPa:

100 PSI ≈ 0.689476 MPa

When comparing equipment, always check whether the stated pressure is a maximum rating, operating pressure, or recommended pressure.

A unit conversion does not tell you whether a particular pressure is safe for a component.

Pressure in Hydraulics

Hydraulic systems often use MPa, bar, or PSI.

For example:

10 MPa = 100 bar

and:

10 MPa ≈ 1,450.38 PSI

High pressure hydraulic equipment can operate at levels far above everyday tire or atmospheric pressure.

For safety critical hydraulic work, use the manufacturer’s specifications and appropriate engineering standards rather than relying only on a converted numerical value.

Pressure in Concrete and Material Strength

Pressure units also appear when reporting compressive strength.

For example:

4,000 PSI ≈ 27.58 MPa

A material specification may therefore use PSI in one document and MPa in another.

It is important to distinguish between a pressure unit and the property being measured. Converting PSI to MPa changes the numerical representation, but it does not change whether the underlying measurement represents pressure, stress, strength, or another related quantity.

Gauge Pressure vs Absolute Pressure

This is one of the most important concepts when working with real pressure measurements.

Absolute pressure is measured relative to a perfect vacuum.

Gauge pressure is measured relative to the surrounding atmospheric pressure.

For example, a tire gauge reading of approximately 32 PSI generally refers to pressure above atmospheric pressure.

If atmospheric pressure is approximately 14.7 PSI, then the corresponding absolute pressure would be roughly:

32 + 14.7 = 46.7 PSI absolute

This distinction matters in engineering, gas systems, vacuum applications, thermodynamics, and fluid calculations.

A unit converter can convert the numerical unit, but it does not automatically determine whether your input is gauge pressure or absolute pressure.

Always check the specification before converting or comparing pressure values.

Common Pressure Conversion Mistakes

Confusing PSI and PSF

PSI means pounds per square inch.

PSF means pounds per square foot.

They are not the same unit.

Because one square foot contains 144 square inches:

1 psi = 144 psf

Confusing bar and millibar

Remember:

1 bar = 1,000 mbar

A millibar is one thousandth of a bar.

Confusing gauge and absolute pressure

A pressure reading can have the same unit but a different reference point.

For example:

32 PSI gauge

is not the same physical pressure as:

32 PSI absolute

Assuming 1 bar equals 1 atmosphere

They are close, but not identical.

1 bar = 100 kPa

while:

1 atm = 101.325 kPa

So:

1 atm ≈ 1.01325 bar

Confusing kPa and MPa

The relationship is:

1 MPa = 1,000 kPa

Therefore:

100 kPa = 0.1 MPa

Rounding too early

Pressure conversions can involve several decimal places.

For example:

1 PSI ≈ 6.894757 kPa

If you repeatedly round intermediate values, the final result may become less accurate.

Keep the available precision until the final step whenever accuracy matters.

How Accurate Is the Pressure Converter?

The CalculatorKits Pressure Converter uses the pascal as its base unit and standard SI conversion constants. The tool states that it avoids rounding until the final display and supports high numerical precision for its calculations.

NIST provides standardized conversion factors for common pressure units such as PSI, bar, atmosphere, torr, and pascal.

For everyday pressure conversions, engineering calculations, education, equipment comparisons, and general reference work, these standard relationships are appropriate.

However, pressure measurement itself depends on the accuracy and calibration of the instrument producing the original value.

A converter can accurately change:

32 PSI → 220.63 kPa

but it cannot make an inaccurate 32 PSI measurement accurate.

For safety critical, laboratory, industrial, medical, or certified measurements, use calibrated instruments and applicable standards.

Why the Pascal Is the Base Unit

The pascal is the SI derived unit for pressure.

The relationship is:

1 Pa = 1 N/m²

A newton is the SI unit of force, so pressure can be understood as force distributed across an area.

The BIPM formally adopted the name “pascal” for the SI unit of pressure in 1971.

Because the pascal is the SI reference unit, many other pressure units can be expressed in terms of pascals.

For example:

1 bar = 100,000 Pa

1 atm = 101,325 Pa

1 psi ≈ 6,894.757 Pa

This makes the pascal a convenient base for a pressure converter.

Privacy and Browser Based Calculations

The CalculatorKits Pressure Converter performs calculations locally in the browser. The tool does not require registration and states that pressure conversion calculations are not uploaded or stored remotely.

This makes it convenient for quick calculations on a phone, tablet, or computer.

The tool also provides a unit search, live preview, commonly used presets, and a copy option for working with conversion results.

Related CalculatorKits Tools

Pressure calculations often appear alongside other measurements. These four CalculatorKits tools can be useful depending on the problem.

Temperature Converter converts Celsius, Fahrenheit, Kelvin, Rankine, Réaumur, and other temperature scales. Temperature and pressure are frequently considered together in thermodynamics and gas calculations.

Force Converter converts newtons, pounds-force, kilogram-force, and other force units. It is useful when you need to understand the force component behind a pressure calculation.

Energy Converter converts joules, kilojoules, kilowatt hours, calories, BTU, and other energy units for systems where pressure and energy are related.

Power Converter converts electrical, mechanical, and thermal power units when pressure is part of a larger mechanical or engineering calculation.

Frequently Asked Questions

How many PSI are in 1 bar?

1 bar = 14.5038 PSI

How many bar are in 1 PSI?

1 PSI ≈ 0.0689476 bar

How many pascals are in 1 bar?

1 bar = 100,000 Pa

How many kPa are in 1 bar?

1 bar = 100 kPa

How many PSI are in 1 atmosphere?

1 atm ≈ 14.6959 PSI

How many pascals are in one atmosphere?

1 atm = 101,325 Pa

How many kPa are in one atmosphere?

1 atm = 101.325 kPa

How many pascals are in 1 PSI?

One PSI is approximately:

6,894.757 Pa

How many PSI are in 1 MPa?

One MPa is approximately:

145.038 PSI

How many bar are in 1 MPa?

1 MPa = 10 bar

Is bar the same as atmosphere?

No. They are close but not identical.

1 bar = 100 kPa

while:

1 atm = 101.325 kPa

Is PSI the same as psf?

No.

PSI means pounds per square inch.

PSF means pounds per square foot.

They differ by the size of the area used.

What is the SI unit of pressure?

The SI unit of pressure is the pascal (Pa).

One pascal equals:

1 N/m²

What is the difference between gauge and absolute pressure?

Gauge pressure is measured relative to surrounding atmospheric pressure. Absolute pressure is measured relative to a perfect vacuum.

Can I convert PSI to kPa?

Yes.

Use approximately:

1 PSI = 6.894757 kPa

For example:

30 PSI ≈ 206.843 kPa

Can I convert kPa to PSI?

Yes.

Use approximately:

1 kPa = 0.145038 PSI

For example:

200 kPa ≈ 29.0076 PSI

Should I round pressure conversions?

For everyday use, one or two decimal places may be sufficient. For engineering or technical calculations, retain additional precision when required by the application.

Key Takeaways

Pressure conversion expresses the same pressure using different measurement units.

The most useful relationships to remember are:

1 bar = 100,000 Pa

1 bar = 100 kPa

1 bar = 0.1 MPa

1 bar = 14.5038 PSI

1 PSI ≈ 6,894.757 Pa

1 atm = 101,325 Pa

1 atm = 101.325 kPa

1 atm ≈ 14.6959 PSI

1 MPa = 10 bar

1 Torr ≈ 133.322 Pa

The most important thing is to identify the exact pressure unit and reference condition before converting. A numerical conversion cannot resolve whether a pressure reading is gauge or absolute, nor can it determine whether a measurement is safe for a particular piece of equipment.

For everyday and technical conversions, the CalculatorKits Pressure Converter handles the conversion automatically. Enter the value, select the From unit, choose the To unit, and use the displayed result.

For safety critical, certified, laboratory, medical, or industrial applications, always verify the result against the appropriate standard, specification, or calibrated instrument.

References

1. National Institute of Standards and Technology, Pressure and Gas Flow Unit Conversions
2. National Institute of Standards and Technology, Pressure and Vacuum Measurements
3. BIPM, The International System of Units
4. BIPM, SI Brochure
5. Encyclopaedia Britannica, Pressure

Written and reviewed by the CalculatorKits Editorial Team
Last Updated: September 10, 2026