atm to Pascals
Convert atmospheres (atm) to pascals (Pa) with this free converter. The conversion uses the exact definition 1 atm = 101,325 Pa, so a pressure in atmospheres is simply multiplied by 101,325 to get pascals. The atmosphere is a familiar unit in chemistry, diving, and weather reporting, while the pascal is the SI unit used in physics and engineering specifications.
Result
Formula & Conversion Factor
The conversion uses the exact definition 1 atm = 101,325 Pa, so the formula is Pa = atm × 101325. To convert in the opposite direction, atm = Pa ÷ 101325. Both directions are exact because the factor is a definition rather than a measured value.
| Direction | Factor | Example |
|---|---|---|
| atm to pascals | multiply by 101,325 | 2 atm = 202,650 Pa |
| pascals to atm | divide by 101,325 | 202,650 Pa = 2 atm |
Worked Example
Convert a pressure of 2.5 atm to pascals:
- Start with the value in atmospheres: 2.5 atm.
- Apply the factor: 2.5 × 101,325 = 253,312.5 Pa.
- Round the result to two decimals: 253,312.50 Pa, or about 253.3 kPa.
A second check with the default value: 10 atm × 101,325 = 1,013,250 Pa, which is the number shown in the result box above.
atm to Pascals Reference Table
Common pressure values in atmospheres converted to pascals with the exact factor 101,325:
| atm | pascals (Pa) | kilopascals (kPa) |
|---|---|---|
| 0.1 | 10,132.5 | 10.1325 |
| 0.5 | 50,662.5 | 50.6625 |
| 1 | 101,325 | 101.325 |
| 2 | 202,650 | 202.65 |
| 5 | 506,625 | 506.625 |
| 10 | 1,013,250 | 1,013.25 |
| 50 | 5,066,250 | 5,066.25 |
| 100 | 10,132,500 | 10,132.5 |
Related Tools
External Resources
Frequently Asked Questions
- How do I convert atm to pascals?
- Multiply the pressure in atmospheres by 101,325. For example, 2 atm × 101,325 = 202,650 Pa. Enter any value in the field above and press Calculate to get the pressure in pascals instantly.
- What is the formula for atm to pascals?
- The formula is: Pa = atm × 101325. The factor is exact because the standard atmosphere is defined as 101,325 pascals. Because the factor never changes, the conversion is a simple multiplication with no rounding error.
- How many pascals are in 1 atm?
- One standard atmosphere equals exactly 101,325 pascals, which is also 101.325 kilopascals, 1.01325 bar, or 760 millimetres of mercury. This is the value used by chemistry, meteorology, and engineering standards worldwide.
- How many atm is 1 pascal?
- One pascal equals 1 ÷ 101,325 atm, or about 9.8692 × 10⁻⁶ atm. In other words, a pascal is a very small pressure, so atmospheric pressures expressed in pascals are large numbers.
- Why is the conversion factor 101,325?
- The standard atmosphere was defined by international agreement as 101,325 Pa, matching the average sea-level pressure. It is exactly equal to 760 mmHg (torr) and 1.01325 bar, so the factor is a fixed definition rather than a measured average.
- When are atm and pascals each used?
- Atmospheres are common in chemistry, scuba diving, weather reporting, and older equipment ratings. The pascal is the SI unit of pressure and is used in physics, engineering specifications, and vacuum technology. Converting between them lets you compare readings across both systems.
- Is atm the same as bar?
- No. One atmosphere equals 1.01325 bar, while one bar equals 100,000 pascals. The two are close but not identical: 1 atm is about 1.3% higher than 1 bar. This calculator uses the exact 101,325 Pa definition of the atmosphere.
- How accurate is this atm to pascals conversion?
- The factor 101,325 is an exact definition, so the mathematics is exact and only the displayed precision is limited. This calculator shows results to four decimal places in pascals, which is more than enough for laboratory, diving, and engineering applications.