PhysicsCalcs
Units & Conversions

Pressure Converter

Convert pascal, kilopascal, bar, psi, atmosphere, torr, mmHg, inHg, and water-column pressure units.

Interactive converter

Pressure Converter

Convert pascal, bar, psi, atm, Torr, mmHg, and water-column units.

Values are treated as magnitudes in the chosen unit. Gauge vs absolute (psig/psia) is not adjusted automatically.

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Enter a value and click Convert.

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Quick Guide

  • Enter a pressure value and select from/to units.
  • Use the swap button to reverse units.
  • Popular shortcuts auto-convert on click.

Table of Contents

Key Takeaways

  • Pressure is force divided by area: P = F / A.
  • The SI unit of pressure is the pascal: 1 Pa = 1 N/m².
  • 1 bar = 100,000 Pa exactly; 1 atm = 101,325 Pa exactly.
  • 1 psi ≈ 6,894.76 Pa.
  • Manometric units (mmHg, inH₂O) depend on conventional density and gravity assumptions.

What Is a Pressure Converter?

It converts pressure values between units using pascals as the internal reference. Useful for physics, engineering, weather, HVAC, hydraulics, and vacuum work.

For related thermodynamic quantities, see the Energy Conversion Calculator.

Pressure Formula

P=F/AP = F / A

P = pressure, F = force, A = area. 1 pascal = 1 newton per square meter.

Common Pressure Units

Pa and kPa are SI units. bar is common in engineering. psi is common for tires and hydraulics. atm, Torr, and mmHg are used in vacuum and medical contexts. inH₂O is common in HVAC duct static pressure.

Gauge vs Absolute Pressure

Absolute pressure is relative to vacuum. Gauge pressure is relative to atmospheric pressure. This converter does not automatically change reference type — enter values as magnitudes in the chosen unit.

Examples

1 atm

1 atm = 101,325 Pa = 101.325 kPa.

1 bar

1 bar = 100,000 Pa = 100 kPa.

1 psi

1 psi ≈ 6,894.76 Pa ≈ 6.895 kPa.

760 Torr

760 Torr = 1 atm.

Common Pressure Reference Values

ContextTypical valueNotes
Sea-level atmosphere≈ 1 atm ≈ 14.7 psiStandard atmosphere definition
Car tire (gauge)≈ 32 psiIllustrative; varies by vehicle
Vacuum (rough)mTorr rangeLaboratory vacuum systems

Limitations

Fixed conventional conversion factors. Manometric units depend on density and gravity assumptions. Torr and mmHg are extremely close but not strictly identical. Not for safety-critical calibration without professional verification.

FAQ

What is the SI unit of pressure?›

The pascal (Pa). 1 Pa = 1 N/m².

How many pascals are in 1 bar?›

1 bar = 100,000 Pa exactly.

How do I convert psi to bar?›

Multiply psi by 0.0689476, or use this converter. 1 psi ≈ 68,947.6 Pa and 1 bar = 100,000 Pa.

How many pascals are in 1 atm?›

1 standard atmosphere = 101,325 Pa exactly.

How many pascals are in 1 psi?›

1 psi ≈ 6,894.757 Pa.

What is psig vs psia?›

psig is gauge pressure relative to atmosphere. psia is absolute pressure relative to vacuum. This converter treats values as magnitudes and does not add or subtract atmospheric offset.

Is bar the same as atm?›

No. 1 bar = 100 kPa; 1 atm = 101.325 kPa.

Is Torr the same as mmHg?›

They are extremely close (760 Torr = 1 atm) but not strictly identical under all definitions.

What is gauge pressure?›

Gauge pressure is measured relative to local atmospheric pressure. Absolute pressure is relative to vacuum.

Can I use this for tire pressure?›

Yes, for unit conversion. Tire gauges often read gauge pressure in psi or kPa.

What temperature are water-column units based on?›

Most water-column units here use 4°C. A separate inH₂O (60°F) option is available for HVAC contexts.

Sources

  1. NIST: pressure unit conversions
  2. BIPM: SI Brochure
Manish Kumar

Author & technical reviewer

Manish Kumar

PhysicsCalcs tools are reviewed with an educational focus: clear formulas, transparent assumptions, and practical context for students and science learners.

Learn more about Manish