Convert Pressure from bar to kilopascals (bar to kPa)

Bar to Kilopascal Conversion Formula

To convert a pressure from bar to kilopascals (kPa), multiply by 100.

• kPa = bar × 100

The relationship is exact by definition: the bar is defined as 100,000 Pa, which is 100 kPa. No rounding, no measured constant — shifting the decimal point two places is the conversion.

Step-by-Step Example

A European compressor is regulated to 6.5 bar and a maintenance sheet written for the Canadian market wants kPa:

1. Take the pressure: 6.5 bar
2. Multiply by 100: 6.5 × 100 = 650 kPa

Quick Reference Table

Two Metric Dialects of the Same Pressure

Bar and kilopascal are both metric, both gauge-friendly, and separated only by convention about which industries use which. Tire pressure is the classic split: continental European placards say 2.2 bar where Canadian, Japanese and Australian placards say 220 kPa — identical inflation, different dialect. Pneumatics documentation tends to bar in Europe and kPa in SI-strict contexts; plumbing and water-supply specs mix freely. Because the factor is exactly 100, the conversion itself never introduces error — the mistakes in practice are decimal-place slips in mental math (6 bar is 600 kPa, not 60) and the perennial gauge/absolute mix-up, which this conversion, like every pressure-unit conversion, leaves untouched: 2.2 bar gauge is 220 kPa gauge, and about 321 kPa absolute.

A note on formality: the kPa is the SI-sanctioned unit; the bar is merely "accepted for use with SI", and standards bodies have been gently deprecating it for years. Industry has ignored the deprecation just as steadily — bar remains the working unit of European compressed air, diving and hydraulics — so fluency in both dialects, and the two-decimal shift between them, stays a daily necessity.

How many bar are in one kilopascal? One kilopascal (kPa) contains 0.01 bar (bar) — the inverse of the factor above. Multiplying by 100 takes you from bar to kilopascals; multiplying by 0.01 brings you back.

Put in words: one bar equals 100 kilopascals, so the bar is the larger unit of this pair. Converting between them never changes the amount of pressure being measured — only the size of the unit you count it in.

What is a bar (bar)?

The bar is a metric unit of pressure.

It is defined as exactly 100 kilopascals (kPa), or 100,000 Pascals (Pa).

Although it is not an official part of the International System of Units (SI), it is widely accepted for use with the SI. The bar is a popular unit for measuring pressure because it is very close to the average atmospheric pressure on Earth at sea level.

Origin of the Bar

The term "bar" comes from the Greek word βάρος (baros), which means "weight."

The unit was introduced by British meteorologist William Napier Shaw in 1909. It is still widely used in meteorology, oceanography, and engineering.

Bar vs. Standard Atmosphere (atm)

A common point of confusion is the difference between a bar and a standard atmosphere (atm).

While they are very close in value, they are not the same:

• 1 bar = 100,000 Pascals (Pa)
• 1 atmosphere (atm) = 101,325 Pascals (Pa)

This means 1 bar is approximately equal to 0.987 atm. Because it's so close to atmospheric pressure and is a round number (100 kPa), the bar is a very convenient unit for many applications.

Common Applications of the Bar

The bar is a versatile unit used to measure pressure in many industrial and everyday contexts.

Common examples include:

• Automotive: Measuring tire pressure (often listed on a car's door jamb alongside PSI).
• Scuba Diving: Expressing the amount of air pressure inside diving tanks.
• Weather: Used by meteorologists for weather forecasting and reading atmospheric pressure.
• Plumbing & Pumps: Measuring water pressure in pipes and pump systems.
• Industrial: Measuring air pressure in pneumatic equipment and gas pressure in cylinders for welding.

What is a kilopascal (kPa)?

A kilopascal (kPa) is a metric unit of pressure that equals 1,000 pascals.

It is one of the most common units for measuring pressure worldwide, used in both scientific and everyday applications.

The Kilopascal (kPa) Explained

The base unit, the pascal (Pa), is named after the French polymath Blaise Pascal.

As part of the metric system (also known as the SI system), the kilopascal is widely used in scientific, engineering, and industrial fields due to its standardization and ease of calculation.

Common Applications of Kilopascals (kPa)

The kPa unit is used to measure pressure in many everyday and technical contexts. Common examples include:

• Tire Pressure: A common measurement for vehicle tire pressure in many countries outside the US.
• Weather Forecasting: Used for reporting atmospheric pressure.
• HVAC Systems: Essential for measuring differential pressure in heating, ventilation, and air conditioning systems.
• Medical: Frequently used for measuring blood pressure.
• Manufacturing: Critical for monitoring pressure in various industrial processes.

Kilopascal Conversions (kPa to PSI and Bar)

For practical use, it's essential to understand how kPa converts to other common pressure units.

• kPa to PSI: 1 kPa is approximately 0.145 PSI (Pounds per Square Inch). PSI is the standard pressure unit used in the United States.
• kPa to Bar: 100 kPa is exactly equal to 1 bar. The bar is another metric unit frequently used for atmospheric and water pressure.

bar to kilopascal Conversion Table

Here are some quick reference conversions from bar (bar) to kilopascal (kPa):

This conversion in other languages

Engineering datasheets across Europe write bar to kilopascal several different ways. The calculation is the same in every one of them.