Atmospheres to Kilopascals Converter
Convert standard atmospheres to kilopascals — one atmosphere is exactly 101.325 kPa. Results update as you type; exact factors shown.
One standard atmosphere is 101.325 kilopascals — see the exact factor, not a rounded rule of thumb.
How the atmospheres to kilopascals converter works
Pressures convert through the pascal (1 N/m²). One bar is exactly 100 kPa; a standard atmosphere is exactly 101.325 kPa; 1 psi is 6.894757 kPa (a pound-force on a square inch); 1 mmHg is 133.322 Pa by the conventional definition.
The UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common pressure conversions
| From | To | Units |
|---|---|---|
| 0.1 atm | 10.1325 kPa | standard atmospheres to kilopascals |
| 0.25 atm | 25.3313 kPa | standard atmospheres to kilopascals |
| 0.5 atm | 50.6625 kPa | standard atmospheres to kilopascals |
| 0.75 atm | 75.9938 kPa | standard atmospheres to kilopascals |
| 1 atm | 101.325 kPa | standard atmosphere to kilopascals |
| 1.5 atm | 151.9875 kPa | standard atmospheres to kilopascals |
| 2 atm | 202.65 kPa | standard atmospheres to kilopascals |
| 3 atm | 303.975 kPa | standard atmospheres to kilopascals |
| 5 atm | 506.625 kPa | standard atmospheres to kilopascals |
| 10 atm | 1,013.25 kPa | standard atmospheres to kilopascals |
| 50 atm | 5,066.25 kPa | standard atmospheres to kilopascals |
| 100 atm | 10,132.5 kPa | standard atmospheres to kilopascals |
Units in this converter and their exact factors
| Unit | Symbol | One unit in pascals |
|---|---|---|
| pascal | Pa | 1 pascal |
| kilopascal | kPa | 1,000 pascal |
| megapascal | MPa | 1,000,000 pascal |
| bar | bar | 100,000 pascal |
| millibar (hectopascal) | mbar | 100 pascal |
| standard atmosphere | atm | 101,325 pascal |
| pound per square inch | psi | 6,894.757293168 pascal |
| millimetre of mercury | mmHg | 133.322387415 pascal |
| inch of mercury | inHg | 3,386.389 pascal |
FAQFrequently asked questions about pressure conversion
How many kilopascals in an atmosphere?
Exactly 101.325.
Is that the same as a bar?
Almost — a bar is 100 kPa, about 1.3% less.
What is atmospheric pressure at altitude?
About 0.5 atm at 5,500 m, halving roughly every 5.5 km.
Why is the atmosphere defined exactly?
It was fixed at 101,325 Pa in 1954 so it could serve as a precise reference.
What is 2 atm?
202.65 kPa — the pressure at about 10 m underwater plus the air above.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.