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Pascals to Bar Converter

↔ Convert bar to Pa instead

Common Conversions

Pa bar
100 0.001
1000 0.01
10000 0.1
50000 0.5
100000 1
101325 1.01325
200000 2
500000 5
1000000 10
5000000 50
10000000 100

Why this conversion matters in chemistry

The pascal is the SI base for pressure; the bar is what IUPAC chose as the reference pressure for standard-state thermodynamic tables back in 1982. The factor between them is exactly 10⁵ — 1 bar is 100,000 Pa by construction. Vacuum-system datasheets quote ultimate pressures in pascals (turbo pumps reach 10⁻⁷ Pa or below), but the lab summary often translates back into bar. A turbopump base pressure of 5 × 10⁻⁷ Pa is 5 × 10⁻¹² bar — the kind of figure that confirms residual-gas contamination is below the threshold for ion-source stability in a mass-spec setup.

Formula

bar = Pa / 100000

Worked Examples

100000 Pa = 1 bar

The defining identity — exactly 10⁵ Pa per bar by construction.

101325 Pa = 1.01325 bar

One standard atmosphere expressed in bar — slightly above the IUPAC reference, by exactly 1.3%.

50000 Pa = 0.5 bar

Half a bar — a moderate reduced pressure for vacuum-distillation work on a high-boiling solvent.

200000 Pa = 2 bar

About the elevated pressure inside a small autoclave during a sterilization or hydrothermal-synthesis run.

Frequently Asked Questions

How do I convert Pa to bar?
Divide by 100,000. The relationship is exact, so 100,000 Pa is precisely 1 bar with no rounding.
Is 1 bar exactly 100,000 Pa?
Yes — the bar is defined as exactly 10⁵ Pa, equivalently 100 kPa. The conversion introduces no measurement uncertainty.
What's the difference between bar and atm?
1 bar is 100,000 Pa and 1 atm is 101,325 Pa, so an atmosphere is about 1.3% higher than a bar. The gap matters for tabulated thermodynamic standard-state values, which post-1982 IUPAC anchors on the bar.
Why does the bar matter in modern chemistry?
IUPAC switched from 1 atm to 1 bar as the standard reference pressure in 1982. Every tabulated standard formation enthalpy, Gibbs free energy, or equilibrium constant published since then implicitly uses the bar as its anchor.