Pressure Converter – PSI, Bar, kPa, mmHg, atm & 15+ Units

A Pressure Converter helps you instantly convert between pressure units such as Pascal (Pa), kilopascal (kPa), megapascal (MPa), bar, PSI (pounds per square inch), standard atmosphere (atm), millimeters of mercury (mmHg), torr, and inches of mercury (inHg). It is used in engineering, automotive maintenance, medical devices, meteorology, HVAC, hydraulic systems, and scientific research worldwide.

The SI (International System of Units) unit of pressure is the pascal (Pa). Larger values are commonly expressed as kilopascal (kPa) or megapascal (MPa). One pascal equals one newton per square meter (N/m²). It is the standard unit in scientific, engineering, and medical literature globally.

To convert PSI (pounds per square inch) to bar, multiply by 0.0689476. Example: 30 PSI × 0.0689476 ≈ 2.07 bar. PSI is standard in the USA and UK; bar is widely used in Europe and most international industrial contexts.

To convert bar to PSI, multiply by 14.5038. Example: 2 bar × 14.5038 ≈ 29.01 PSI. This conversion is used whenever a European bar-rated specification needs to be communicated in US or UK PSI terms, or vice versa.

Absolute pressure is measured relative to a perfect vacuum (0 Pa). Gauge pressure is measured relative to ambient atmospheric pressure — a gauge reading of 0 means the system is at atmospheric pressure, not a vacuum. To convert gauge to absolute pressure, add approximately 101.325 kPa (14.696 PSI) at sea level. Most tyre and hydraulic gauges display gauge pressure (psig / barg), while scientific and thermodynamic calculations use absolute pressure (psia / bara / kPa abs).

Millimeters of mercury (mmHg) is the universal clinical standard for blood pressure measurement. Normal resting blood pressure is defined as 120/80 mmHg. Despite the SI system designating kPa as the preferred unit, mmHg remains dominant in medical practice worldwide including in the USA, UK, EU, India, China, and Japan because of established clinical reference ranges.

To convert mmHg to kilopascal (kPa), multiply by 0.133322. Example: 120 mmHg (systolic blood pressure) × 0.133322 ≈ 16.0 kPa. This conversion is used in clinical research, anaesthesia records, and international medical device specifications.

To convert pascal (Pa) to PSI, multiply by 0.000145038. Because one pascal is a very small unit, most practical engineering uses kPa or MPa. Example: 100,000 Pa (= 1 bar) × 0.000145038 ≈ 14.504 PSI.

Atmospheric pressure in weather reports is expressed in hectopascals (hPa), which are identical to millibars (mbar). Standard sea-level atmospheric pressure is 1013.25 hPa. The USA also uses inches of mercury (inHg) for aviation and some weather broadcasts. Most of the rest of the world uses hPa exclusively.

To convert standard atmospheres (atm) to pascals, multiply by 101,325 (exact). Example: 2 atm = 202,650 Pa = 202.65 kPa. Atmospheres are used in chemistry (gas law calculations), diving depth calculations, and some older scientific literature.

The unit depends on your country and vehicle handbook. USA and UK: PSI is most common (typical car tyre: 30–35 PSI). Continental Europe and Japan: bar (typical: 2.0–2.5 bar). Australia and other metric countries: kPa (typical: 200–250 kPa). All three express the same physical pressure — this converter handles all three. Always refer to your vehicle's specified pressure, not a generic recommendation.

Yes. Conversion factors are based on exact SI definitions and NIST/ISO reference values. The tool is accurate for engineering calculations, scientific work, tyre and hydraulic pressure checks, and medical reference conversions. For safety-critical applications (pressure vessel design, medical equipment calibration), always verify against certified standards and consult a qualified engineer.

Yes. This pressure converter supports all units used across the USA, UK, EU, India, Japan, Australia, UAE, and other regions. Whether you need PSI for US HVAC specifications, bar for European industrial equipment, kPa for Australian tyre guidelines, or mmHg for medical reference, this tool covers every major pressure unit with ISO-accurate precision.