A standard atmosphere is exactly 101,325 pascals.
Atmospheres to PSI Converter — atm to psi
Convert Atmosphere (atm) to PSI (psi) using the exact conversion factor (1 atmosphere = 14.69594878 psi). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Atmospheres to PSI 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.
Pounds per square inch.
Result = input x 101325 / 6894.757293.
Pressure uses the pascal as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Atmospheres to PSI
Atmosphere and PSI 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 PSI is typically associated with united States (standard pressure unit for tires, tools, and plumbing).
Formula
psi = atmospheres × 14.6959487755
This factor comes from each unit's defined relationship to the category's base unit: 1 atmosphere equals 101325 base units, and 1 psi equals 6894.75729317 base units, so dividing one by the other gives the direct atmosphere-to-psi factor of 14.6959487755.
Simple example
1 atm × 14.69594878 = 14.69594878 psi
1 atmosphere = 14.69594878 psi.
Real-world example
35 atm × 14.69594878 = 514.3582071 psi
35 atmospheres = 514.3582071 psi.
Conversion table
| Atmosphere (atm) | PSI (psi) |
|---|---|
| 1 atm | 14.69594878 psi |
| 5 atm | 73.47974388 psi |
| 10 atm | 146.9594878 psi |
| 25 atm | 367.3987194 psi |
| 50 atm | 734.7974388 psi |
| 100 atm | 1,469.594878 psi |
Reverse conversion: PSI to Atmosphere
14.69594878 psi × 0.06804596391 = 1 atm
14.69594878 psi = 1 atmospheres.
atmospheres = psi × 0.0680459639099
For a page dedicated to this direction, see PSI to Atmosphere.
Atmosphere vs. PSI
| Aspect | Atmosphere | PSI |
|---|---|---|
| Family | non-SI unit accepted for use with the SI | US/imperial customary unit |
| Typical use | Chemistry (standard conditions are often defined at 1 atm) | Tire pressure specifications in the US |
| Where it's used | Widely used internationally in chemistry, meteorology, and diving/aviation contexts alongside the pascal and bar | United States (standard pressure unit for tires, tools, and plumbing) |
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 PSI
PSI (psi) measures pressure. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. It is classified as a US/imperial customary unit.
Where it's used: United States (standard pressure unit for tires, tools, and plumbing)
Uses of the PSI today
- Tire pressure specifications in the US
- Hydraulic and pneumatic system ratings
- Plumbing, compressed-air tools, and industrial equipment ratings
History of the PSI
PSI is a derived unit from the pound-force and the inch, both themselves standardized through English and later international agreements rather than invented as a pressure unit from scratch.
It became the default pressure unit in US engineering as pound-force and inch-based measurement dominated American industry through the 19th and 20th centuries, and it remains in everyday use for tires and tools even as most other measurements in the US context stay imperial.
Historical origin. PSI 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.
PSI — sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units — Documents conversion factors for psi and other US customary pressure units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many psi are in 1 atmosphere?
1 atmosphere equals 14.69594878 psi, using the exact defined conversion factor rather than an estimate.
How do I convert atmosphere to psi?
Multiply the atmosphere value by 14.69594878. The converter above does this instantly to whatever precision you set.
How do I convert psi back to atmosphere?
Use the reverse factor: 1 psi equals 0.0680459639 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 psi?
PSI (psi) measures pressure. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. It is classified as a US/imperial customary unit.
Is the atmosphere to psi conversion exact?
Yes. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. 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