Bar to Atmosphere (bar to atm)
Result
0.9869232667 Atmosphere
Formula
atm = bar × 0.9869232667
1 bar = 0.9869232667 atm, and 1 atm = 1.01325 bar.
The pascal is one newton per square metre. The bar is exactly 100,000 Pa, the standard atmosphere exactly 101,325 Pa, the torr exactly 1/760 atm, and psi is one pound-force per square inch (6,894.757 Pa).
Worked examples
- 1 bar × 0.9869232667 = 0.98692327 atm
- 10 bar × 0.9869232667 = 9.8692327 atm
- 100 bar × 0.9869232667 = 98.692327 atm
Common mistakes
- Tyre and compressor gauges read gauge pressure — pressure above the surrounding air. Absolute pressure is about 1 atm (14.7 psi, 1.013 bar) higher.
- Weather maps use hectopascals (1 hPa = 100 Pa = 1 millibar); standard sea-level pressure is 1,013.25 hPa.
- Torr and mmHg differ by less than one part per million and are interchangeable for practical purposes.
Bar to Atmosphere table
| Bar (bar) | Atmosphere (atm) |
|---|---|
| 1 | 0.98692327 |
| 2 | 1.9738465 |
| 5 | 4.9346163 |
| 10 | 9.8692327 |
| 20 | 19.738465 |
| 50 | 49.346163 |
| 100 | 98.692327 |
| 1,000 | 986.92327 |
The units
- Bar (bar)
- Exactly 100,000 Pa, about the atmospheric pressure at sea level.
- Atmosphere (atm)
- The standard atmosphere: exactly 101,325 Pa.
Sources for these factors
- The International System of Units (SI Brochure), 9th edition — BIPM
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy