A standard atmosphere is exactly 101,325 pascals.
Atmospheres to Pascals Converter — atm to Pa
Convert Atmosphere (atm) to Pascal (Pa) using the exact conversion factor (1 atmosphere = 101,325 pascal). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Atmospheres to Pascals converter
Converter
Pressure Converter
Convert pascals, bars, PSI, atmospheres, mercury columns, water columns, and engineering pressure units.
Context values
Some unit families need one extra value for a physically accurate result.
The pascal is one newton per square meter.
Result = input x 101325 / 1.
Pressure uses the pascal as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Atmospheres to Pascals
Atmosphere and Pascal both show up on pressure gauges — psi is standard on US tire and tool specifications, while bar is the everyday pressure unit across most of the rest of the world. Atmosphere is typically associated with widely used internationally in chemistry, meteorology, and diving/aviation contexts alongside the pascal and bar, while Pascal is typically associated with standard scientific pressure unit worldwide.
Formula
pascals = atmospheres × 101325
This factor comes from each unit's defined relationship to the category's base unit: 1 atmosphere equals 101325 base units, and 1 pascal equals 1 base unit, so dividing one by the other gives the direct atmosphere-to-pascal factor of 101325.
Simple example
1 atm × 101325 = 101,325 Pa
1 atmosphere = 101,325 pascals.
Real-world example
35 atm × 101325 = 3,546,375 Pa
35 atmospheres = 3,546,375 pascals.
Conversion table
| Atmosphere (atm) | Pascal (Pa) |
|---|---|
| 1 atm | 101,325 Pa |
| 5 atm | 506,625 Pa |
| 10 atm | 1,013,250 Pa |
| 25 atm | 2,533,125 Pa |
| 50 atm | 5,066,250 Pa |
| 100 atm | 10,132,500 Pa |
Reverse conversion: Pascal to Atmosphere
1 Pa × 0.000009869232667 = 0.0000098692 atm
1 pascal = 0.0000098692 atmospheres.
atmospheres = pascals × 0.00000986923266716
For a page dedicated to this direction, see Pascal to Atmosphere.
Atmosphere vs. Pascal
| Aspect | Atmosphere | Pascal |
|---|---|---|
| Family | non-SI unit accepted for use with the SI | SI derived unit |
| Typical use | Chemistry (standard conditions are often defined at 1 atm) | Scientific and engineering pressure measurement worldwide |
| Where it's used | Widely used internationally in chemistry, meteorology, and diving/aviation contexts alongside the pascal and bar | Standard scientific pressure unit worldwide |
Understanding the Atmosphere
Atmosphere (atm) measures pressure. Defined as exactly 101,325 pascals, originally based on the average atmospheric pressure at mean sea level. It is classified as a non-SI unit accepted for use with the SI.
Where it's used: Widely used internationally in chemistry, meteorology, and diving/aviation contexts alongside the pascal and bar
Uses of the Atmosphere today
- Chemistry (standard conditions are often defined at 1 atm)
- Diving and aviation pressure references
- General reference for everyday atmospheric pressure
Understanding the Pascal
Pascal (Pa) measures pressure. The pascal is the SI derived unit of pressure: one newton of force per square meter. It is classified as a SI derived unit.
Where it's used: Standard scientific pressure unit worldwide
Uses of the Pascal today
- Scientific and engineering pressure measurement worldwide
- Meteorology (often as hectopascals, equivalent to millibars)
- Material science (stress and strength, typically in megapascals)
History of the Pascal
The pascal is named after Blaise Pascal, whose 17th-century experiments clarified the physics of fluid pressure and vacuum. It was adopted as the SI derived unit of pressure in 1971, replacing the older, non-coherent CGS pressure units used in much scientific work up to that point.
Historical origin. Pascal was not the invention of a single named person; it developed through the process described above.
Atmosphere — sources
- BIPM SI Brochure — Standard atmosphere listed among non-SI units with a fixed exact value in pascals.
Pascal — sources
- BIPM SI Brochure — Coherent derived units — Defines the pascal as the SI unit of pressure.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many pascals are in 1 atmosphere?
1 atmosphere equals 101,325 pascals, using the exact defined conversion factor rather than an estimate.
How do I convert atmosphere to pascal?
Multiply the atmosphere value by 101325. The converter above does this instantly to whatever precision you set.
How do I convert pascal back to atmosphere?
Use the reverse factor: 1 pascal equals 0.0000098692 atmospheres. You can also use the swap control in the converter above to flip the direction instantly.
What is a atmosphere?
Atmosphere (atm) measures pressure. Defined as exactly 101,325 pascals, originally based on the average atmospheric pressure at mean sea level. It is classified as a non-SI unit accepted for use with the SI.
What is a pascal?
Pascal (Pa) measures pressure. The pascal is the SI derived unit of pressure: one newton of force per square meter. It is classified as a SI derived unit.
Is the atmosphere to pascal conversion exact?
Yes. Defined as exactly 101,325 pascals, originally based on the average atmospheric pressure at mean sea level. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
Where is the atmosphere still used today?
Widely used internationally in chemistry, meteorology, and diving/aviation contexts alongside the pascal and bar