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Bar To Atm Conversion

Convert pressures between bar and atmospheres, plus Pa and psi for context.

Formula shown0 inputs definedUpdated Nov 2025By CalcuTotal TeamFree, no sign-up

Quick Summary

Use this when you need:

Translate compressor discharge pressures reported in bar into atm for safety documents
Compare process datasheets that mix bar, atm, and kPa
Convert brewing or HVAC gauges labeled in bar into familiar atm or psi values

You’ll get:Pressure

How this is calculated

Formula:

pressure_target = pressure_source

In plain language:

Pressures are normalized to Pascals (1 bar = 100,000 Pa; 1 atm = 101,325 Pa) before scaling into bar, atm, psi, or kilopascals.

The formula is always visible so you can verify the math and explain your numbers to anyone who asks.

What these terms mean

Pressure

Pressure used in the calculation.

When to use this calculator

Translate compressor discharge pressures reported in bar into atm for safety documents
Compare process datasheets that mix bar, atm, and kPa
Convert brewing or HVAC gauges labeled in bar into familiar atm or psi values

Last updated: November 21, 2025

Bar to atm converter explained

European datasheets love bar; US specs lean on atmospheres or psi. This converter keeps those pressures aligned so you can sanity-check setpoints, safety valves, and compressor ratings quickly.

How the conversion works

Bar is defined as $100{,}000\,\text{Pa}$ ; atmosphere is $101{,}325\,\text{Pa}$ . Conversions ride on those Pa anchors:

P_{\text{atm}} = P_{\text{bar}} \times \frac{100{,}000}{101{,}325} \approx P_{\text{bar}} \times 0.986923

P_{\text{bar}} = P_{\text{atm}} \times 1.01325

Units and conversions

Unit	Symbol	Relation to Pa
Bar	bar	$1\,\text{bar} = 100{,}000\,\text{Pa}$
Atmosphere	atm	$1\,\text{atm} = 101{,}325\,\text{Pa}$
Kilopascal	kPa	$1\,\text{kPa} = 1{,}000\,\text{Pa}$
Pascal	Pa	base unit
Pound per square inch	psi	$1\,\text{psi} = 6{,}894.757\,\text{Pa}$

Worked examples

Compressor discharge in bar → atm
Given $2.4\,\text{bar}$ :
$P_{\text{atm}} = 2.4 \times 0.986923 \approx 2.37\,\text{atm}$
Result: 2.37 atm.
Vacuum reading in atm → bar
Given $0.85\,\text{atm}$ :
$P_{\text{bar}} = 0.85 \times 1.01325 \approx 0.861\,\text{bar}$
Result: 0.861 bar.

Tips and pitfalls

Always note whether a gauge reads absolute (bara) or relative (barg); converting gauge values needs the atmospheric offset added back.
Keep at least three significant figures when setting relief valves or interlocks.
If you collaborate across regions, default to kPa in documentation; it is SI and unambiguous.

References and further reading

Frequently Asked Questions

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Calculator info

Version:: v1.0.0
Last reviewed:: Nov 21, 2025
Sensitivity:: low
References:: 2

Last updated: November 21, 2025

Bar to atm converter explained

European datasheets love bar; US specs lean on atmospheres or psi. This converter keeps those pressures aligned so you can sanity-check setpoints, safety valves, and compressor ratings quickly.

How the conversion works

Bar is defined as $100{,}000\,\text{Pa}$ ; atmosphere is $101{,}325\,\text{Pa}$ . Conversions ride on those Pa anchors:

P_{\text{atm}} = P_{\text{bar}} \times \frac{100{,}000}{101{,}325} \approx P_{\text{bar}} \times 0.986923

P_{\text{bar}} = P_{\text{atm}} \times 1.01325

Units and conversions

Unit	Symbol	Relation to Pa
Bar	bar	$1\,\text{bar} = 100{,}000\,\text{Pa}$
Atmosphere	atm	$1\,\text{atm} = 101{,}325\,\text{Pa}$
Kilopascal	kPa	$1\,\text{kPa} = 1{,}000\,\text{Pa}$
Pascal	Pa	base unit
Pound per square inch	psi	$1\,\text{psi} = 6{,}894.757\,\text{Pa}$

Worked examples

Compressor discharge in bar → atm
Given $2.4\,\text{bar}$ :
$P_{\text{atm}} = 2.4 \times 0.986923 \approx 2.37\,\text{atm}$
Result: 2.37 atm.
Vacuum reading in atm → bar
Given $0.85\,\text{atm}$ :
$P_{\text{bar}} = 0.85 \times 1.01325 \approx 0.861\,\text{bar}$
Result: 0.861 bar.

Tips and pitfalls

Always note whether a gauge reads absolute (bara) or relative (barg); converting gauge values needs the atmospheric offset added back.
Keep at least three significant figures when setting relief valves or interlocks.
If you collaborate across regions, default to kPa in documentation; it is SI and unambiguous.

Quick Summary

Calculator Tool

How this is calculated

What these terms mean

Pressure

When to use this calculator

Bar to atm converter explained

How the conversion works

Units and conversions

Worked examples

Tips and pitfalls

References and further reading

Frequently Asked Questions

Related Calculators

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atm to Pascals Conversion

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bar to psi Conversion

Bar to PSIG Converter

Pressure Converter

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Calculator info

Bar to atm converter explained

How the conversion works

Units and conversions

Worked examples

Tips and pitfalls

References and further reading

Frequently Asked Questions

Related Calculators

ATM Conversion

atm to Pascals Conversion

Barometric Pressure Conversion

bar to psi Conversion

Bar to PSIG Converter

Pressure Converter

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