Bar to atm Converter

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Convert bar to atmospheres at the rate 1 bar ≈ 0.9869 atm (inverse of 1 atm = 1.01325 bar). For practical purposes 1 bar and 1 atm are interchangeable in weather and most industrial contexts — they differ by 1.3 %. Useful in chemistry where some textbooks default to atm and others to bar. Browser-local conversion.

Bar
Atmosphere (atm)

Bar → Atmosphere (atm)

Quick reference table

BarAtmosphere (atm)
0.5 bar0.4935 atm
1 bar0.9869 atm
1.5 bar1.4804 atm
2 bar1.9738 atm
5 bar4.9346 atm
10 bar9.8692 atm
50 bar49.3462 atm

Glossary

Bar

The bar is a non-SI metric pressure unit equal to exactly 100,000 Pa, very close to atmospheric pressure at sea level (1 atm = 1.01325 bar). Widely used in European engineering, automotive specs (turbo boost, fuel-rail pressure), tire pressure (2–3 bar typical), scuba diving and weather charts. Not part of SI but accepted for use with SI.

Atmosphere (atm)

A standard atmosphere is defined as exactly 101,325 Pa (= 1.01325 bar = 760 mmHg = 14.696 psi). It represents average atmospheric pressure at sea level under standard conditions. Used in chemistry (gas-law problems), high-altitude aviation references and pressure-vessel ratings. Not the same as the technical atmosphere (at, ≈ 98,066.5 Pa) — that is a separate, rarely used unit.

Metric / SI pressure

In the metric system, pressure is reported in pascals (SI base) or its multiples — kilopascal (kPa, 10³ Pa), megapascal (MPa, 10⁶ Pa) — and the related non-SI unit bar (10⁵ Pa). The millibar/hectopascal (mbar = hPa = 100 Pa) is used in meteorology. All metric units relate by exact powers of ten, so conversions between them are simple shifts of decimal point.

Imperial / US pressure

US engineering and automotive primarily report pressure in pounds per square inch (psi). 1 psi ≈ 6,894.76 Pa, defined as one pound-force per square inch. Standard atmospheric pressure is 14.696 psi. The closely related "psi-gauge" (psi-g) measures pressure above atmospheric, while "psi-absolute" (psi-a) measures total pressure including atmospheric.

Related tools

atm to Bar
Convert atm to bar — 1 atm = 1.01325 bar exactly
Bar to psi
Convert bar to psi — 1 bar ≈ 14.504 psi
Bar to kPa
Convert bar to kPa — 1 bar = 100 kPa
Pressure Converter
Convert pressure — Pa, kPa, MPa, bar, mbar, atm, mmHg, psi