Pressure Converter — Free Online Tool

What Is Pressure Converter?

A free online pressure converter. Convert between pascals, kilopascals, bar, psi, atmospheres, mmHg, and torr. Real-time conversion with a full reference table.

Pressure is a fundamental physical quantity used in engineering, meteorology, scuba diving, tire inflation, and medical applications — each field using different units depending on convention and scale. Pressure Converter handles seven common pressure units with bidirectional real-time conversion.

The supported units cover the full range of pressure measurement contexts. Pascals (Pa) and kilopascals (kPa) are the SI units used in science and engineering worldwide. Bar is commonly used in meteorology and industrial applications. PSI (pounds per square inch) is the standard for tire pressure and US engineering. Atmospheres (atm) represent standard sea-level air pressure. Millimeters of mercury (mmHg) are used in blood pressure measurement and vacuum systems. Torr is equivalent to mmHg and is used in vacuum science and physics.

Each unit has its typical range of use. Tire pressure is typically 30-35 PSI or 2-2.4 bar. Atmospheric pressure at sea level is 1 atm = 101.325 kPa = 14.696 PSI. Blood pressure is measured in mmHg (e.g., 120/80). Vacuum systems operate in the torr range, from 1 torr (rough vacuum) down to 0.001 torr (high vacuum). Industrial hydraulic systems operate in the hundreds of bar.

The relationships between units are based on exact physical definitions. 1 atm = 101,325 Pa exactly. 1 bar = 100,000 Pa. 1 torr = 1/760 atm = 133.322 Pa. The tool applies these exact factors, ensuring that scientific and engineering calculations are accurate regardless of the unit system used.

Real-World Use Cases for Pressure Converter

Checking Tire Pressure with a European vs US Gauge

Your car recommends 2.3 bar tire pressure. Your US-bought gauge reads in PSI. Enter 2.3 in the bar field to get 33.4 PSI. Inflate to 33-34 PSI. For winter driving, the recommended pressure may be slightly higher — check the conversion again with the adjusted value.

Converting Weather Barometric Pressure for Aviation

A weather report gives barometric pressure as 1013.25 hPa (hectopascals, equivalent to millibars). Enter 1013.25 in the kPa field (divide by 10 first: 101.325 kPa). The tool shows 1 atm, 29.92 inHg (or 760 mmHg). Pilots need the altimeter setting in inHg for aircraft instrument calibration.

Converting Blood Pressure Readings Between Units

A medical textbook gives blood pressure as 120/80 mmHg. The device used reads in kPa. Enter 120 in the mmHg field to get 16.0 kPa. Enter 80 mmHg to get 10.7 kPa. The conversion is essential when working with medical equipment calibrated in different units.

Why Use Pressure Converter?

7 units: Pa, kPa, bar, psi, atm, mmHg, torr
Real-time conversion as you type
Full reference table for all units
Swap direction with one click

How to Use Pressure Converter — Step by Step

Enter a pressure value.

Select from and to units.

View the result instantly.

Copy any value from the reference table.

Who Is Pressure Converter Best For?

engineering
tire pressure
meteorology
scuba diving

Pro Tips for Pressure Converter

1Tire pressure for cars is typically 30-35 PSI or 2.0-2.4 bar. Check your vehicle manual or the sticker inside the driver door for the exact recommended pressure.
21 standard atmosphere (atm) is exactly 14.696 PSI, 101.325 kPa, or 760 mmHg. This is the average pressure at sea level.
3Blood pressure is always measured in mmHg (millimeters of mercury) in medical contexts. 120/80 mmHg is considered normal. To convert to kPa, multiply by approximately 0.1333.
4Vacuum pressure is often expressed as a negative gauge pressure. For example, -10 PSI gauge means 10 PSI below atmospheric, which is 4.696 PSI absolute (14.696 - 10).

Pressure Converter — Frequently Asked Questions

How many psi are in a bar?

1 bar = 14.5038 psi. To convert bar to psi, multiply by 14.5038.

What is atmospheric pressure?

1 atmosphere (atm) = 101,325 pascals = 1.01325 bar = 14.696 psi. This is the standard atmospheric pressure at sea level.

How accurate are the unit conversions?

Conversions use NIST-standard conversion factors with precision up to 15 significant digits. Currency exchange rates update every 10 minutes from a free data source.

Can I convert between any two units?

Yes. Each converter supports all standard units within its category. For example, the length converter handles metric, imperial, and nautical units.

Is Pressure Converter really free to use?

Yes, Pressure Converter is completely free with no hidden charges, no usage limits, and no premium tiers. You can use it as often as you need without signing up or providing any personal information.

Ready to Use Pressure Converter?

Free online tool — works in your browser, no sign-up required. Start using it right now.

Try It Now