Pressure • NIST Exact

Bars Atmospheres

bar → atm

1 bar = 0.9869232667 atmNIST Exact

bar → atm Reference Table

bar atm
0.01 bar 0.009869232667 atm
0.1 bar 0.09869232667 atm
0.5 bar 0.4934616334 atm
1 bar 0.9869232667 atm
2 bar 1.973846533 atm
5 bar 4.934616334 atm
10 bar 9.869232667 atm
20 bar 19.73846533 atm
50 bar 49.34616334 atm
100 bar 98.69232667 atm
500 bar 493.4616334 atm
1000 bar 986.9232667 atm

Values based on NIST SP 811 conversion factors

🌍 Real-World Examples

Standard atmospheric pressure

1.01325 bar = 1 atm

Car tire gauge pressure

2.3 bar = 2.269923513 atm

Pressure at about 100 m underwater

10 bar = 9.869232667 atm

Full scuba tank pressure

200 bar = 197.3846533 atm

Why Convert Bars to Atmospheres?

Converting between bars (bar) and atmospheres (atm) is one of the most common pressure conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert bar to atm saves time and prevents errors.

Pressure conversions between bar and atm are critical in automotive maintenance, meteorology, and diving. Tire pressure recommendations differ by region — European cars typically specify bar while US vehicles use PSI. Weather services report atmospheric pressure in different units: hPa/mbar in most countries, mmHg (inHg) in the US. Scuba divers must understand ATM conversions to calculate safe diving depths and decompression schedules.

How to Convert Bars to Atmospheres

To convert bars to atmospheres, use the following formula:

atm = bar × 0.9869232667

Example: 1 bar = 0.9869232667 atm

For example, 5 bar = 4.934616334 atm, 10 bar = 9.869232667 atm, and 100 bar = 98.69232667 atm. Our calculator above performs this conversion instantly with full precision — no rounding errors.

Common Use Cases

  • Standard atmospheric pressure: 1.01325 bar = 1 atm
  • Car tire gauge pressure: 2.3 bar = 2.269923513 atm
  • Pressure at about 100 m underwater: 10 bar = 9.869232667 atm
  • Full scuba tank pressure: 200 bar = 197.3846533 atm

Common Mistakes to Avoid

  • Gauge vs absolute: Tire pressure gauges read relative to atmospheric pressure (gauge pressure). Add 1 atm (~14.7 psi) to get absolute pressure.
  • Bar vs ATM confusion: 1 bar ≈ 0.987 atm — they're close but not equal. For precise work, don't interchange them.
  • Unit proliferation: Pressure has many units (Pa, bar, psi, atm, mmHg, torr). Always confirm which unit your equipment uses.

Pro Tips

  • Memorize the factor: 1 bar = 0.9869232667 atm. For quick mental math, remember this base conversion.
  • Quick reference: 5 bar = 4.934616334 atm · 10 bar = 9.869232667 atm · 25 bar = 24.67308167 atm · 50 bar = 49.34616334 atm · 100 bar = 98.69232667 atm
  • Bookmark this page: Save this converter for instant access. It works offline once loaded — no internet needed.

Bars to Atmospheres Conversion Table

baratm
0.01 bar0.009869232667 atm
0.1 bar0.09869232667 atm
0.5 bar0.4934616334 atm
1 bar0.9869232667 atm
2 bar1.973846533 atm
5 bar4.934616334 atm
10 bar9.869232667 atm
20 bar19.73846533 atm
50 bar49.34616334 atm
100 bar98.69232667 atm
500 bar493.4616334 atm
1000 bar986.9232667 atm

All values in this table are mathematically exact per NIST SP 811.

Frequently Asked Questions

How many atmospheres are in 1 bar?

1 bar equals 0.9869232667 atm. This is an exact conversion factor defined by NIST.

How do I convert bars to atmospheres?

Multiply the value in bar by the conversion factor. For example, 10 bar = 9.869232667 atm. Use our calculator above for instant results.

Is the bars to atmospheres conversion exact?

Yes, this conversion is mathematically exact based on the international definition of these units (NIST SP 811).

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