How To Convert Pounds per Square Inch (psi) to Bar (bar)
Formula: bar = psi × 0.06894757293168
Example: Convert 40 psi to bar.
40 × 0.06894757293168 = 2.7579029172672 bar
To do this conversion by hand, you only need one number, 0.06894757293168.
Multiply your psi value by this number to get bar.
If you want a rough mental estimate, you can use 1 psi ≈ 0.07 bar, then refine if needed.
Quick Answer
1 psi = 0.06894757293168 bar
- 15 psi = 1.0342135939752 bar
- 32 psi = 2.20632233381376 bar
- 100 psi = 6.894757293168 bar
Conversion Formula
bar = psi × 0.06894757293168
Recommended (SI standard): 0.06894757293168 bar per psi.
This means every 1 psi is a little under 0.07 bar. Because bar is a metric pressure unit and psi is an imperial pressure unit, the conversion uses the exact relationship between force and area in the SI system.
- Write down the pressure in psi.
- Multiply by 0.06894757293168.
- The result is the same pressure in bar.
Pound per square inch
A pound per square inch is a pressure unit that means one pound of force applied to an area of one square inch. Its symbol is psi.
It became common in the United States through engineering and industry, especially for steam, hydraulics, and compressed air systems. It is still widely used on gauges and specifications.
- Tire pressure on cars, bikes, and trucks
- Air compressor and pneumatic tool ratings
- Hydraulic system pressure in machinery
- Water pressure regulators and plumbing tests
- Industrial pressure gauges and safety limits
Bar
A bar is a metric pressure unit close to atmospheric pressure. Its symbol is bar.
The bar was introduced to give an easy-to-use pressure unit near 100,000 pascals, which fits many real-world pressure measurements. It is common in weather, engineering, and many countries that use metric units.
- Tire pressure in many countries (often shown as bar)
- SCUBA and diving tank pressure (often bar)
- Industrial compressed air systems
- Hydraulics and pressure testing in metric specs
- Weather and atmospheric pressure reporting (related units like mbar)
Is this Conversion of Pounds per Square Inch (psi) To Bar (bar) Accurate?
Yes. This conversion is based on fixed, internationally agreed definitions of pressure units in the SI system. Our team uses the exact conversion factor that comes from the definitions of the pound-force, the inch, and the pascal, then relates that to the bar (exactly 100,000 pascals). Because the unit definitions are standardized and not estimated, the result is reliable for study, engineering work, and everyday use. For more details about how we choose and verify standards, see our accuracy standards.
Real Life Examples
Here are practical situations where converting psi to bar helps you understand a reading or match a specification.
- Car tires: If a tire label says 32 psi, that is 2.20632233381376 bar, useful if your air pump shows bar.
- Air compressor setup: A regulator set to 90 psi equals 6.2052815638512 bar, so you can match a tool manual written in bar.
- Pressure washer rating: A small washer rated at 1,600 psi is 110.316116690688 bar, helpful for comparing with metric models.
- Hydraulic equipment: A line pressure of 2,500 psi equals 172.3689323292 bar, common in heavy machinery specifications.
- Plumbing pressure test: A test at 50 psi equals 3.447378646584 bar, so you can report results in metric form.
- Paint spray gun: If your gauge reads 20 psi, that is 1.3789514586336 bar, which some paint guides prefer.
- Bicycle tires: A road bike at 100 psi equals 6.894757293168 bar, making it easy to use a floor pump marked in bar.
Quick Tips
- Fast estimate: psi × 0.07 ≈ bar (close for quick checks).
- Reverse estimate: bar × 14.5 ≈ psi.
- Remember: 1 bar is close to normal air pressure, about 14.5 psi.
- For accurate work, use the full factor 0.06894757293168.
- When reporting, keep consistent rounding, for example 2 to 6 decimal places based on your need.