Pascals to atm
Convert pascals (Pa) to atmospheres (atm) with this free converter. The conversion uses the exact definition 1 atm = 101,325 Pa, so a pressure in pascals is divided by 101,325 to get atmospheres. The pascal is the SI unit used in physics and engineering, while the atmosphere is a familiar unit in chemistry, diving, and weather reporting.
Result
Formula & Conversion Factor
The conversion uses the exact definition 1 atm = 101,325 Pa, so the formula is atm = Pa ÷ 101325. To convert in the opposite direction, Pa = atm × 101325. Both directions are exact because the factor is a definition rather than a measured value.
| Direction | Factor | Example |
|---|---|---|
| pascals to atm | divide by 101,325 | 202,650 Pa = 2 atm |
| atm to pascals | multiply by 101,325 | 2 atm = 202,650 Pa |
Worked Example
Convert a laboratory pressure of 250,000 Pa to atmospheres:
- Start with the value in pascals: 250,000 Pa.
- Apply the divisor: 250,000 ÷ 101,325 = 2.46775 atm.
- Round the result to three decimals: 2.468 atm.
A second check with the default value: 101,325 Pa ÷ 101,325 = 1 atm, which is the number shown in the result box above.
Pascals to atm Reference Table
Common pressure values in pascals converted to atmospheres with the exact divisor 101,325:
| pascals (Pa) | atm |
|---|---|
| 1,000 | 0.009869 |
| 10,000 | 0.098692 |
| 50,000 | 0.493462 |
| 101,325 | 1.000000 |
| 200,000 | 1.973847 |
| 500,000 | 4.934616 |
| 1,000,000 | 9.869233 |
| 10,132,500 | 100.000000 |
Related Tools
External Resources
Frequently Asked Questions
- How do I convert pascals to atm?
- Divide the pressure in pascals by 101,325. For example, 202,650 Pa ÷ 101,325 = 2 atm. Enter any value in the field above and press Calculate to get the pressure in atmospheres instantly.
- What is the formula for pascals to atm?
- The formula is: atm = Pa ÷ 101325. The divisor is exact because the standard atmosphere is defined as 101,325 pascals. Because the factor never changes, the conversion is a simple division with no rounding error.
- How many atm are in 1 pascal?
- One pascal equals 1 ÷ 101,325 atm, or about 9.8692 × 10⁻⁶ atm. Because a pascal is a very small pressure, you need about 101,325 pascals to make a single atmosphere.
- 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 exact value is used by chemistry, meteorology, and engineering standards worldwide.
- Why is the conversion factor 101,325?
- The standard atmosphere was defined by international agreement as 101,325 Pa, matching 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 pascals and atm each used?
- The pascal is the SI unit of pressure and appears in physics, engineering specifications, and vacuum technology. Atmospheres are common in chemistry, scuba diving, weather reporting, and older equipment ratings. Converting between them lets you compare readings across both systems.
- Is 100,000 Pa the same as 1 atm?
- No. 100,000 Pa equals exactly 1 bar, which is about 0.9869 atm. One atmosphere is 101,325 Pa, roughly 1.3% higher than one bar. This calculator uses the exact 101,325 Pa definition of the atmosphere.
- How accurate is this pascals to atm 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 six decimal places in atmospheres, which is more than enough for laboratory, diving, and engineering applications.