Science · Units

Pressure Converter

Convert tire, plumbing, and engineering pressures across common units.

  • Pascals (Pa)206842.718795
  • Kilopascals (kPa)206.842718795
  • Megapascals (MPa)0.206842718795
  • Bar2.06842718795
  • PSI30
  • Atmospheres (atm)2.0413789173
  • Torr (mmHg)1551.44797715

What is Pressure Converter?

A pressure converter translates force per unit area among pascals, kilopascals, megapascals, bar, pounds per square inch, standard atmospheres, and torr. These units appear in tires, weather, plumbing, hydraulics, vacuum systems, and engineering specifications.

The pascal is the SI derived unit equal to one newton per square meter. Because one pascal is small for many applications, kilopascals and megapascals are common. Bar and psi remain widespread in equipment and everyday pressure readings.

The converter changes units only. It does not determine whether a reading is absolute pressure, gauge pressure, or differential pressure. Those reference conventions must match before two values can be meaningfully compared.

Why Use This Tool?

Use pressure conversion when a tire placard lists kPa but a gauge reads psi, or when equipment documentation mixes bar, MPa, and atmospheric units.

The all-unit table helps identify scale errors. A pressure of 2.5 bar is 250 kPa, not 2.5 kPa, and is about 36.26 psi.

  • Compare tire and equipment pressure ratings
  • Translate SI and customary engineering specifications
  • Convert atmospheric and vacuum-related units
  • Check orders of magnitude across Pa, kPa, and MPa

How Does This Tool Work?

All supported values pass through pascals. The source is multiplied by its pascal factor and then divided by each destination factor. One standard atmosphere is exactly 101,325 Pa and one bar is exactly 100,000 Pa.

The implementation uses 6,894.757293168 Pa per psi and 133.322368421 Pa per torr. Its display labels torr as mmHg, a common practical association, although precise mercury-column units can depend on their formal definition and conditions.

Understanding Your Results

Each result is numerically equivalent only if the same pressure reference is used. Gauge pressure is measured relative to local atmosphere, while absolute pressure is measured relative to vacuum.

For example, a tire reading of 35 psig is gauge pressure; its absolute pressure near standard atmosphere is roughly 49.7 psia. The converter will not add or subtract atmospheric pressure automatically.

Why Tracking This Matters

Incorrect pressure units or references can damage equipment and create safety hazards. Always retain whether a specification is gauge, absolute, or differential and follow manufacturer tolerances.

Benefits of Using Pressure Converter

  • Seven widely used pressure units
  • Exact standard-atmosphere and bar definitions
  • Coverage from pascals to megapascals
  • Live comparison for psi, bar, atm, and torr
  • Browser-side processing
  • Useful for practical and technical checks

How Is the Result Calculated?

Linear unit conversion uses pascals as the common base. Reference-pressure changes are separate from unit conversion.

destination pressure = source pressure × source-to-Pa factor ÷ destination-to-Pa factor

Pascal
One newton per square meter and the shared base unit.
Gauge pressure
Pressure relative to surrounding atmospheric pressure.
Absolute pressure
Pressure relative to a perfect vacuum.
  • 1 atm = 101,325 Pa
  • 1 bar = 100,000 Pa
  • 1 psi ≈ 6,894.757293168 Pa

Tips for Better Results

  • Verify whether a value is gauge or absolute pressure.
  • Never use conversion alone to override equipment safety limits.
  • Check whether a tire value is cold inflation pressure.
  • Keep Pa, kPa, and MPa prefixes visible to avoid thousand-fold errors.
  • Use a calibrated instrument appropriate for the pressure range.
  • Treat torr and mmHg equivalence according to the precision your application requires.

Standards and References

Conclusion

Use the pressure converter to translate among SI, psi, bar, atmosphere, and torr units through a pascal base.

Unit equivalence is only part of correct interpretation: preserve the gauge or absolute reference and follow applicable equipment and safety guidance.

Privacy & how it works

This unit converter runs in your browser. Values you enter are not uploaded to The ToolSphere servers for this tool. Privacy Policy.

FAQ

What is one atmosphere in psi?expand_more

One standard atmosphere is approximately 14.69595 psi and exactly 101,325 Pa.

How many pascals are in one bar?expand_more

One bar is exactly 100,000 pascals, or 100 kPa.

What is the difference between psig and psia?expand_more

Psig is gauge pressure relative to local atmosphere; psia is absolute pressure relative to vacuum.

Does the converter account for atmospheric pressure?expand_more

No. It changes units but does not change gauge, absolute, or differential reference.

Is torr exactly the same as mmHg?expand_more

They are commonly treated as nearly equivalent. Torr is defined as 1/760 of a standard atmosphere; precise mmHg usage may require more context.

How many psi is 2.5 bar?expand_more

Using the factors in this tool, 2.5 bar is approximately 36.2594 psi.

Can pressure be negative?expand_more

Absolute pressure cannot be below zero. Gauge pressure can be negative when it is below the reference atmosphere.

Can I use this for tire inflation?expand_more

It can convert the unit, but follow the vehicle placard, use the specified gauge reference, and measure under recommended conditions.

Is this calculator free?expand_more

Yes. No signup required.

Are my numbers uploaded?expand_more

No. Calculations run in your browser. Inputs are not sent to The ToolSphere servers for this tool.

Is this professional advice?expand_more

No. Results are estimates for general information. See our Disclaimer for health, finance, and related tools.

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