Unit Converter

Pressure Converter

Enter a value in any pressure unit and instantly see the equivalent in pascals, bar, psi, atmospheres, mmHg and more.

Bar PSI Atmospheres mmHg
Conversion Results
Unit Value
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About the Pressure Converter

Pressure units multiply fast across industries — tire pressure in psi, weather reports in hPa, industrial gauges in bar, medical blood pressure in mmHg, and scientific work in pascals. This tool lets you enter a value once and see it converted to every common pressure unit at the same time.

How to Use This Tool

  1. Enter the pressure value you want to convert.
  2. Select the unit that value is currently in.
  3. The table updates automatically, showing the equivalent value in every other unit.

This tool converts absolute pressure, where 0 represents a perfect vacuum, so negative values are rejected. See the FAQ below for the distinction between absolute and gauge pressure.

Conversion Formula

Every pressure unit converts through the pascal (Pa), the SI unit of pressure. To convert from unit A to unit B:

value_B = value_A × factor_A→Pa ÷ factor_B→Pa

All pressure units here are linear multiples of the pascal, so every conversion is straightforward multiplication or division.

Pressure Unit Conversion Factors (to Pascals)

Unit Symbol Value in Pascals
PascalPa1
HectopascalhPa100
KilopascalkPa1,000
MegapascalMPa1,000,000
Barbar100,000
Standard Atmosphereatm101,325
Pound per Square Inchpsi6,894.757293
Millimeter of MercurymmHg133.322387
Inch of MercuryinHg3,386.388640
Kilogram-force per Square Centimeterkgf/cm²98,066.5

Note: atm, psi, mmHg (conventional Torr) and kgf/cm² are all exact by definition, using the standard gravity constant (9.80665 m/s²) and the conventional mercury density (13,595.1 kg/m³).

Worked Examples

Example 1 — Bar to PSI

A tire inflated to 2.2 bar: 2.2 × 100,000 Pa ÷ 6,894.757293 Pa/psi ≈ 31.9 psi.

Example 2 — Atmospheres to kPa

Standard sea-level pressure, 1 atm: 101,325 Pa ÷ 1,000 = 101.325 kPa.

Example 3 — mmHg to kPa (Blood Pressure)

A blood pressure reading of 120 mmHg: 120 × 133.322387 Pa ÷ 1,000 ≈ 16.0 kPa.

Example 4 — MPa to kgf/cm² (Hydraulics)

A hydraulic system rated at 20 MPa: 20,000,000 Pa ÷ 98,066.5 Pa ≈ 203.9 kgf/cm².

Frequently Asked Questions

What's the difference between absolute and gauge pressure?
Absolute pressure is measured from a perfect vacuum (0 Pa) — this is what this tool converts. Gauge pressure is measured relative to atmospheric pressure, so it reads 0 at normal atmospheric conditions and can go negative in a partial vacuum. A tire pressure gauge reads gauge pressure; add 1 atm (≈101.3 kPa) to get the absolute value.
How do I convert bar to psi?
Multiply by 14.5038. So 1 bar ≈ 14.5 psi, and 1 psi ≈ 0.0689 bar.
What is 1 atmosphere in other units?
1 atm = 101,325 Pa = 101.325 kPa = 1.01325 bar ≈ 14.696 psi = 760 mmHg exactly.
Why is blood pressure measured in mmHg?
Historically, mercury column manometers were the standard instrument for measuring pressure precisely, and the mmHg unit stuck in medicine even after most other fields moved to SI units like kPa.
What is kgf/cm² used for?
Kilogram-force per square centimeter is a technical (non-SI) pressure unit still common in some hydraulic, industrial and older engineering specifications, especially in regions that used the metric technical system before fully adopting SI. It's roughly equal to 1 atm (0.9678 atm exactly).
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