How do I convert bar to atm?

Use the formula shown above or enter a value to see bar converted to atm instantly.

What is the formula for bar to atm?

The converter calculates atm by applying the category-specific conversion factor for Pressure.

bar and atm are both part of the Pressure category; pick the unit that matches your measurement context (e.g., scale, region, or industry standard).

Pressure Conversion Cheat Sheet

Use the live converter below to translate between Bar (bar) and Atmosphere (atm). Scroll further for quick examples, formula tips, and related units.

Formula insight: Most unit conversions use a simple multiplication or division by a conversion factor. The calculator shows the exact formula used.

Convert

Bar

bar

Atmosphere

0.9869

atm

Rounded result (4 decimals max)

Formula

1 bar = 0.9869 atm

Conversion sourcesTap or click to view references

The International System of Units (SI) — NIST Special Publication 330
National Institute of Standards and Technology (NIST). The SI Brochure (SP 330) is the definitive English edition of the BIPM SI tables. NIST’s edition lists the official constants and conversion factors tying inch-pound units to SI, which SwapUnits applies for length, mass, temperature, pressure, volume, and related conversions. See /standards/nist-si-tenfold for the complete decimal multiple/submultiple table. View source · View SI table

Results update as you type. Swap the direction to convert back from atm to bar.

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Keep the reciprocal handy when double-checking calculations or undoing a conversion.

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View the full unit roster, charts, and tips for Pressure Conversion Cheat Sheet conversions.