One standard atmosphere is exactly 101,325 Pa. Chemistry and physics problems switch between the two when using SI units.
How to use the atm to Pascals Converter
- Type the number of standard atmospheres into the Standard atmospheres field. Decimals such as 0.5 are fine.
- Read the answer in Pascals – it updates as you type, with no button to press.
- To convert the other way, type into Pascals and the standard atmospheres are recalculated.
- Press Copy results to copy both values with the page title, or Copy link to share this exact conversion.
This page converts only atm ⇄ Pa. Need a different unit? Use the general pressure converter, where you can choose any “from” and “to” unit.
How it works
Both units measure pressure, so they are always in the same ratio: one standard atmosphere equals 101,325 pascals. The calculator multiplies the number of standard atmospheres you type by 101,325 to give pascals, and when you type into the pascals field it divides by the same factor to give standard atmospheres. Because the ratio never changes, doubling the standard atmospheres always doubles the pascals. Results are calculated at full precision and rounded only for display (up to eight decimal places, with very large or small values shown in scientific notation).
How to convert standard atmospheres to pascals
- Write down the value in standard atmospheres, for example 1 atm.
- Multiply by the conversion factor 101,325 (because 1 standard atmosphere = 101,325 Pa).
- 1 × 101,325 = 101,325 Pa.
- To go back from pascals to standard atmospheres, divide by 101,325 – or multiply by 9.869233 × 10-6.
atm to Pa conversion table
| Standard atmospheres | Pascals | Pascals | Standard atmospheres |
|---|---|---|---|
| 0.25 atm | 25,331.25 Pa | 1 Pa | 9.869233 × 10-6 atm |
| 0.5 atm | 50,662.5 Pa | 2 Pa | 1.973847 × 10-5 atm |
| 1 atm | 101,325 Pa | 5 Pa | 4.934616 × 10-5 atm |
| 1.5 atm | 151,987.5 Pa | 10 Pa | 9.869233 × 10-5 atm |
| 2 atm | 202,650 Pa | 20 Pa | 0.00019738465 atm |
| 3 atm | 303,975 Pa | 50 Pa | 0.00049346163 atm |
| 5 atm | 506,625 Pa | 100 Pa | 0.00098692327 atm |
| 10 atm | 1,013,250 Pa | 1,000 Pa | 0.0098692327 atm |
What is a standard atmosphere?
The standard atmosphere is exactly 101,325 Pa, the average air pressure at sea level. Chemistry problems and diving depth calculations often use atm.
What is a pascal?
The pascal is the SI unit of pressure: one newton per square metre. It is small, so kilopascals and megapascals are used in practice.
Quick mental conversion
For a fast estimate, multiply standard atmospheres by about 100,000 to get pascals; the error is about 1.3%. Use the calculator above when you need the exact figure.
Common mistakes to avoid
Mixing gauge pressure (psig, barg) with absolute pressure (psia, bara), treating bar and atm as identical, and confusing kgf/cm² with bar.
Formula
1 atm = 101,325 Pa1 Pa = 9.869233 × 10^-6 atmPa = atm × 101,325Worked example
Inputs — Standard atmospheres: 1 atm.
Results — Pascals = 101,325 Pa.
Frequently asked questions
How many pascals in 1 atm?
101,325 Pa.
How many kPa is 2 atm?
202.65 kPa.
How do I convert standard atmospheres to pascals?
Multiply the number of standard atmospheres by 101,325. For example, 1 atm × 101,325 = 101,325 Pa.
How do I convert pascals back to standard atmospheres?
Divide by 101,325 (or multiply by 9.869233 × 10^-6), or simply type the value into the pascals field above.
What is 10 atm in pascals?
10 atm = 1,013,250 Pa.
What is 5 atm in pascals?
5 atm = 506,625 Pa.
Is this conversion exact?
Yes. The factor comes from the official definitions of both units (NIST and the SI), so the only difference you may see is rounding in the last displayed digit.
Can I convert to other units on this page?
This page converts only between standard atmospheres and pascals. To pick any pressure unit, use the general pressure converter linked under Related calculators.
What formula does the atm to Pascals Converter use?
1 atm = 101,325 Pa.