Bar to Atm Converter
Convert pressure from bar to standard atmospheres (atm). One bar equals about 0.986923 atm, so the two units are close but not identical — the atmosphere is defined as 101,325 Pa while a bar is exactly 100,000 Pa. Enter a value in bar to get the equivalent in atm.
Formula
atm = bar × 0.986923
- 1 bar = 100,000 Pa exactly; 1 standard atmosphere = 101,325 Pa.
- So 1 bar = 100,000 ÷ 101,325 ≈ 0.986923 atm.
- The units are very close — within about 1.3% — which is why they're often used interchangeably in casual contexts.
- To go the other way, multiply atm by 1.01325 to get bar.
Convert 1 bar to atm
Inputs
- Pressure: 1 bar
1 bar × 0.986923 = 0.986923 atm. That's the same as 100,000 Pa, just under one standard atmosphere (101,325 Pa).
Frequently asked questions
How many atm is 1 bar?
1 bar equals approximately 0.986923 atm. They're close because a bar is 100,000 Pa and an atmosphere is 101,325 Pa.
Is bar the same as atmosphere?
Almost, but not exactly. A bar is slightly smaller than a standard atmosphere — about 1.3% less — so for precise work the distinction matters.
How do I convert atm back to bar?
Multiply the value in atm by 1.01325. For example, 2 atm = 2.0265 bar.
Where is the atm unit used?
Standard atmospheres are common in chemistry, physics and diving, while bar is widely used in engineering, weather and tyre pressures.