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Convert Atmospheres to Pascals

Instantly convert Atmospheres (atm) to Pascals (Pa) with our free online calculator.

Reviewed by Christopher FloiedUpdated

Formula: atm to Pamultiply by 101325

Reference Table

Atmospheres (atm)Pascals (Pa)
1101325
5506625
101013250
252533130
505066250
10010132500

How to Convert Atmospheres to Pascals

Formula

To convert Atmospheres (atm) to Pascals (Pa): multiply by 101325

Step-by-Step

  1. Start with your value in Atmospheres (atm).
  2. Multiply by 101325 to perform the conversion.
  3. The result is your value expressed in Pascals (Pa).

Conversion Factor

1 atm = 101325 Pa

Reverse Factor

1 Pa = 0.00000986923 atm

Worked Example

Convert 25 Atmospheres to Pascals: 25 atm = 2533130 Pa

About Atmosphere (atm)

A non-SI unit of pressure defined as exactly 101,325 pascals, corresponding to the standard sea-level atmospheric pressure as adopted by ISO 2533 and the BIPM SI Brochure. Atmospheres are the default reference pressure in physical chemistry (Standard Temperature and Pressure conventions: 1 atm at 273.15 K under IUPAC's 'STP' definition, though IUPAC has since moved to 1 bar STP), in commercial diving (depths are quoted in atmospheres absolute, with each 10 m of seawater adding ~1 atm), and in pressure-sensitive materials research where vapor pressure and saturation data are tabulated at 1 atm. A common pitfall: the "technical atmosphere" (at, 98,066.5 Pa = 1 kgf/cm²) used in some legacy European and Japanese engineering is NOT the same as the standard atmosphere — older pressure-vessel drawings can read 100 at and mean either depending on context. 1 atm = 1.01325 bar = 14.696 psi = 760 mmHg = 760 torr.

About Pascal (Pa)

The SI derived unit of pressure (and stress), formally defined as one newton per square meter (N/m²) by ISO 80000-4. Named for 17th-century French mathematician Blaise Pascal, whose 1647-48 Puy-de-Dôme experiment established that atmospheric pressure decreases with altitude. The pascal is a small unit — standard sea-level atmospheric pressure is exactly 101,325 Pa per the BIPM SI Brochure — so working engineering and meteorology use multiples: kilopascals (kPa) for everyday gauge pressures, megapascals (MPa) for material strength, hectopascals (hPa) for barometric readings (1 kPa = 10 hPa). The pascal is the universal SI reference for pressure across scientific publication (Physical Review, J. Fluid Mechanics), thermodynamic state tables (NIST REFPROP), and international engineering codes (ASME, EN, JIS). Converting Pa to psi is a divide-by-6894.76; Pa to bar is divide-by-100,000.

Quick Facts

  • 1 Atmosphere equals 101325 Pascals
  • 1 Pascal equals 0.00000986923 Atmospheres
  • Atmosphere is a unit of pressure
  • Pascal is a unit of pressure
  • This conversion is commonly used in tire inflation, weather reporting, scuba diving, and engineering
  • The Pascal belongs to the metric system

Common Atmosphere to Pascal Conversions

Atmospheres (atm)Pascals (Pa)
0.110132.5
0.550662.5
1101325
2202650
5506625
101013250
14.6961489070
151519880
202026500
252533130
505066250
10010132500
15015198800
20020265000
50050662500
1000101325000

Understanding Atmospheres

The Atmosphere (symbol: atm) is a unit of pressure. A non-SI unit of pressure defined as exactly 101,325 pascals, corresponding to the standard sea-level atmospheric pressure as adopted by ISO 2533 and the BIPM SI Brochure. Atmospheres are the default reference pressure in physical chemistry (Standard Temperature and Pressure conventions: 1 atm at 273.15 K under IUPAC's 'STP' definition, though IUPAC has since moved to 1 bar STP), in commercial diving (depths are quoted in atmospheres absolute, with each 10 m of seawater adding ~1 atm), and in pressure-sensitive materials research where vapor pressure and saturation data are tabulated at 1 atm. A common pitfall: the "technical atmosphere" (at, 98,066.5 Pa = 1 kgf/cm²) used in some legacy European and Japanese engineering is NOT the same as the standard atmosphere — older pressure-vessel drawings can read 100 at and mean either depending on context. 1 atm = 1.01325 bar = 14.696 psi = 760 mmHg = 760 torr.

Atmospheres are commonly used in tire inflation, weather reporting, scuba diving, and engineering.

Understanding Pascals

The Pascal (symbol: Pa) is a unit of pressure. The SI derived unit of pressure (and stress), formally defined as one newton per square meter (N/m²) by ISO 80000-4. Named for 17th-century French mathematician Blaise Pascal, whose 1647-48 Puy-de-Dôme experiment established that atmospheric pressure decreases with altitude. The pascal is a small unit — standard sea-level atmospheric pressure is exactly 101,325 Pa per the BIPM SI Brochure — so working engineering and meteorology use multiples: kilopascals (kPa) for everyday gauge pressures, megapascals (MPa) for material strength, hectopascals (hPa) for barometric readings (1 kPa = 10 hPa). The pascal is the universal SI reference for pressure across scientific publication (Physical Review, J. Fluid Mechanics), thermodynamic state tables (NIST REFPROP), and international engineering codes (ASME, EN, JIS). Converting Pa to psi is a divide-by-6894.76; Pa to bar is divide-by-100,000.

It belongs to the metric measurement system.

Pascals are commonly used in tire inflation, weather reporting, scuba diving, and engineering.

Why Convert Atmospheres to Pascals?

Engineers, mechanics, and scientists frequently need to convert pressure between Atmospheres and Pascals when working with different measurement standards. Tire pressure, blood pressure readings, weather barometric measurements, and industrial process specifications may all use different pressure units depending on the region or discipline. Reliable conversion prevents equipment misuse and ensures safety.

Frequently Asked Questions

How do I convert Atmospheres to Pascals?

A non-SI unit of pressure defined as exactly 101,325 pascals, corresponding to the standard sea-level atmospheric pressure as adopted by ISO 2533 and the BIPM SI Brochure. To convert Atmospheres to Pascals, multiply by 101325. For example, 25 atm equals 2533130 Pa.

How many Pascals are in 1 Atmosphere?

There are 101325 Pascals in 1 Atmosphere.

How many Atmospheres are in 1 Pascal?

There are 0.00000986923 Atmospheres in 1 Pascal.

What is the formula for Atmosphere to Pascal conversion?

The formula is: multiply by 101325. This means 1 atm = 101325 Pa.

Is a Atmosphere bigger than a Pascal?

No. One Atmosphere is smaller than one Pascal because 1 atm equals 101325 Pa, which is greater than 1.

When do you need to convert between Atmospheres and Pascals?

The SI derived unit of pressure (and stress), formally defined as one newton per square meter (N/m²) by ISO 80000-4. Atmosphere and Pascal are both pressure units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.

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