atm to Bar Converter

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Convert atmospheres to bar using the exact relation 1 atm = 1.01325 bar. The two units are nearly equal — atmospheric pressure at sea level is about 1.013 bar — so for everyday weather and tire-pressure work the difference is negligible. Useful for chemistry and gas-law problems where atm and bar appear interchangeably in textbooks. Browser-local conversion.

Atmosphere (atm)
Bar

Atmosphere (atm) → Bar

Quick reference table

Atmosphere (atm)Bar
0.5 atm0.5066 bar
1 atm1.0133 bar
1.5 atm1.5199 bar
2 atm2.0265 bar
5 atm5.0663 bar
10 atm10.1325 bar
50 atm50.6625 bar

Glossary

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.

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.

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

Bar to atm
Convert bar to atm — 1 bar ≈ 0.9869 atm
atm to kPa
Convert atm to kPa — 1 atm = 101.325 kPa exactly
atm to psi
Convert atm to psi — 1 atm ≈ 14.696 psi
Pressure Converter
Convert pressure — Pa, kPa, MPa, bar, mbar, atm, mmHg, psi