Pascal (Pa) is a pressure unit with the symbol Pa. One pascal is one newton per square meter. It is a very small pressure unit, so engineering and weather contexts often use kilopascals, bars, or megapascals for readability.
Quick facts
- Unit name
- Pascal
- Symbol
- Pa
- Quantity
- pressure
- SI bridge
- 1 Pa is the base reference for this Xunits pressure category.
- Category
- Pressure
- Converter hub
- Pressure converter
Pressure scale
Pressure units are easiest to compare through pascals. This visual places Pa beside neighboring pressure units.
Definition
One pascal is one newton per square meter. It is a very small pressure unit, so engineering and weather contexts often use kilopascals, bars, or megapascals for readability. Use pascals when you need strict SI notation or when a formula is built from newtons and square meters. For everyday tire or compressor readings, kPa, bar, or psi may be easier to read.
Pressure reference
A pressure number can be gauge, absolute, or differential. The unit Pa tells you the scale, but the surrounding notation tells you the reference. Keep labels such as psig, psia, barg, bara, absolute pressure, or differential pressure when the source provides them.
Exact relationships and reference values
| Relationship | Why it matters |
|---|---|
| 1 Pa = 1 N/m2 | Useful reference relationship |
| 1 kPa = 1,000 Pa | Useful reference relationship |
| 1 bar = 100,000 Pa | Useful reference relationship |
| 1 atm = 101,325 Pa | Useful reference relationship |
Where Pa is used
Pascals are common in scientific formulas, SI engineering documents, material stress, acoustics, building physics, sensor specifications, and standards-based pressure reporting.
Common mistakes
- Do not confuse pascal pressure with Pascal as a programming language or a personal name in prose.
- Do not publish large everyday pressures only in Pa when kPa or bar would be more readable.
- Do not remove gauge or absolute labels when converting Pa, kPa, bar, or psi values.
Converters and formulas
Use these pages when you need a direct calculation involving Pa.
Related pressure guides
Compare Pa with other pressure units in the same directory.
FAQ
Is pascal an SI unit?
Yes. The pascal is the SI derived unit of pressure.
Why are many pressure values written in kPa instead of Pa?
Because one pascal is small. Kilopascals make everyday pressure values shorter and easier to scan.
What does Pa mean in pressure?
Pa is the symbol for pascal, equal to one newton per square meter.