Bar to ATM Conversion Calculator

Convert bar to standard atmospheres for engineering, scientific, industrial, pneumatic, and pressure-system calculations.

Convert bar to atmospheres

Enter pressure in bar to calculate the equivalent standard-atmosphere value.

Bar value

About bar to ATM conversion

Bar and standard atmospheres are pressure units used across engineering, science, meteorology, and industrial equipment specifications worldwide. One bar is defined as exactly 100,000 pascals. One standard atmosphere, abbreviated atm, is exactly 101,325 pascals. Because the atmosphere is slightly larger than the bar, a value expressed in bar becomes a slightly smaller numerical value when converted to atm. To convert bar to atmospheres, divide the bar value by 1.01325. Equivalently, multiply by approximately 0.98692327. One bar is about 0.98692327 atm, 1.01325 bar is exactly 1 atm, and 2 bar is about 1.97384653 atm. The calculator performs this relationship directly and retains full numeric precision before displaying a result rounded to eight decimal places. Bar is common on pressure gauges, compressors, industrial process equipment, and European vehicle specifications. Atmospheres are familiar in chemistry and physics, especially gas-law exercises and comparisons with sea-level pressure. Converting between them makes it easier to reconcile a gauge reading or manufacturer specification with a formula or reference table that uses atm. Both units can describe absolute or gauge pressure, but the unit name alone does not identify the reference. Absolute pressure is measured from a vacuum. Gauge pressure is measured relative to the surrounding atmosphere. A reading of 2 bar gauge therefore does not represent the same physical state as 2 bar absolute. Unit conversion preserves the reference type, so identify it before using the converted number in an equation. This calculator accepts zero and positive decimal values. Zero bar converts mathematically to zero atm, although physical applications may distinguish an ideal vacuum from an instrument's practical limit. For safety-sensitive pneumatic, hydraulic, diving, or process work, verify the instrument, reference condition, tolerances, and applicable standards. The conversion factor is exact, but the useful precision of the result can never exceed the quality of the source measurement.

Bar to ATM examples

Useful bar pressures shown in standard atmospheres.

Bar	Atmospheres	Context
1 bar	0.98692327 atm	A common metric pressure reference
1.01325 bar	1 atm	Exactly one standard atmosphere
2 bar	1.97384653 atm	A moderate compressed-air pressure
5 bar	4.93461633 atm	An industrial pressure comparison

How to convert bar to ATM

Enter the non-negative pressure measured in bar.
Select Convert to ATM to divide by 1.01325.
Read the equivalent standard-atmosphere pressure.
Use Reset to clear the value for another conversion.

Bar to ATM FAQ

How many atmospheres are in one bar?

One bar equals approximately 0.98692327 standard atmospheres. Bar is slightly smaller than the standard-atmosphere unit.

What formula converts bar to ATM?

Divide the pressure in bar by 1.01325. The same calculation can be expressed by multiplying bar by approximately 0.98692327.

Are bar and ATM metric units?

Bar is a metric pressure unit defined from pascals, while atm is a non-SI reference unit. Both are widely used alongside SI pressure measurements.

Is 1.01325 bar exactly one ATM?

Yes, both values equal exactly 101,325 pascals. This relationship follows from the definitions of bar and the standard atmosphere.

Does the conversion account for gauge pressure?

The arithmetic works for either gauge or absolute values, but it does not change the reference. Keep the same pressure reference when interpreting the result.