Convert Standard Atmospheres to Kilopascals
Standard Atmosphere (atm) to Kilopascal (kPa) unit conversion — enter any value below to get an instant result, or use the table for common values.
Results from this calculator are estimates provided for general informational purposes only, based on formulas, rates, and standards commonly accepted as of 2026. Figures may differ slightly from other calculators or professional sources due to rounding methods, differing assumptions, or regional regulations, and rules may change over time. Always consult a qualified professional — such as a financial advisor, healthcare provider, or other relevant specialist — before making decisions based on these results.
Result
1 atm = 101.325 kPa
1 Standard Atmosphere = 101.325 Kilopascals
1 Kilopascal = 0.0098692327 Standard Atmospheres
1 atm in every supported unit
Conversion chart: Standard Atmosphere to Kilopascals
Conversion table
| Standard Atmosphere (atm) | Kilopascal (kPa) |
|---|---|
| 0.01 atm | 1.01325 kPa |
| 0.1 atm | 10.1325 kPa |
| 1 atm | 101.325 kPa |
| 2 atm | 202.65 kPa |
| 3 atm | 303.975 kPa |
| 5 atm | 506.625 kPa |
| 10 atm | 1013.25 kPa |
| 20 atm | 2026.5 kPa |
| 50 atm | 5066.25 kPa |
| 100 atm | 10132.5 kPa |
| 1000 atm | 101325 kPa |
Standard Atmosphere (atm)
Definition: Defined as exactly 101,325 pascals, representing the average atmospheric pressure at sea level on Earth.
History: Originally based on the height of a column of mercury observed by 17th-century scientists such as Evangelista Torricelli, and later fixed to a precise pascal value for scientific consistency.
Current use: Used as an intuitive reference point in chemistry, physics, and aviation to describe pressures relative to normal sea-level conditions, such as cabin pressurization or gas-law calculations.
Kilopascal (kPa)
Definition: Equal to 1,000 pascals, a convenient mid-sized metric pressure unit for everyday engineering measurements.
History: Adopted as a standard SI prefix multiple once the pascal itself was formalized in 1971, filling the practical gap between the pascal's tiny scale and the much larger megapascal.
Current use: Widely used on tire pressure gauges outside the US, in HVAC and hydraulic system specifications, and on equipment nameplates across most of the metric world.
Supported Units
| Unit | Symbol | In Pascals |
|---|---|---|
| Pascal | Pa | 1 Pa |
| Kilopascal | kPa | 1000 Pa |
| Megapascal | MPa | 1000000 Pa |
| Hectopascal | hPa | 100 Pa |
| Bar | bar | 100000 Pa |
| Millibar | mbar | 100 Pa |
| Pound per Square Inch | psi | 6894.7573 Pa |
| Standard Atmosphere | atm | 101325 Pa |
| Torr | Torr | 133.32237 Pa |
| Inch of Mercury | inHg | 3386.38 Pa |
About These Parameters
- Value
- The pressure reading you want to convert, expressed in the "From" unit. Accepts decimals.
- From Unit
- The pressure scale your input value is currently measured in — for example, PSI on a US tire gauge or hectopascals on a weather report.
- To Unit
- The pressure scale you want the result converted into. Use the swap button to flip From and To instantly.
How Pressure Conversion Works
The Formula
Every unit here is defined by a fixed multiplier relative to the pascal. To convert a value from one unit to another:
result = value × (factor of "From" unit ÷ factor of "To" unit)
For Standard Atmosphere → Kilopascal: multiply by 101.325. For example, 1 atm × 101.325 = 101.325 kPa.
SI vs. Customary Units
The metric units on this page — pascal, kilopascal, megapascal, hectopascal, bar, and millibar — all scale by powers of ten, so converting between them is just moving a decimal point. PSI is a US customary unit built from pounds-force and square inches, unrelated to the metric scale, while torr and inches of mercury are older manometer-based units defined by the height of a mercury column a pressure could support — each needs its own precise multiplier rather than a round decimal shift.
Why Atmospheric Pressure Matters
Standard atmospheric pressure — 101,325 Pa, or 1 atm — is the reference point most pressure units are built around, because it is the pressure every person and machine on Earth's surface experiences by default. Meteorologists track small deviations from this baseline, measured in hectopascals or millibars, to forecast weather: a falling barometer reading signals an approaching low-pressure system and possible storms, while a rising one signals clear, stable conditions.
Example
1 atm equals 101.325 kPa. For scale, that's about 1× standard atmospheric pressure (1 atm, or 1 atm) — roughly the pressure difference a typical car tire holds above the surrounding air (about 32 psi, or 2.2 bar).
Frequently Asked Questions
How many Kilopascals are in 1 Standard Atmosphere?
1 Standard Atmosphere (atm) equals exactly 101.325 Kilopascals (kPa).
Why do US tire gauges use PSI?
The United States never mandated metrication, so pounds and inches stayed the default units for everyday measurement, including the pound-force-per-square-inch pressure scale used on tire gauges, plumbing fixtures, and compressed air tools. Most of the rest of the world reads the same measurement in bar or kilopascals.
What's the difference between a bar and an atmosphere?
A bar is a round metric unit equal to exactly 100,000 pascals, chosen for convenient arithmetic; a standard atmosphere is fixed at exactly 101,325 pascals, the measured average air pressure at sea level. The two are close — 1 atm is about 1.01325 bar — but they are defined differently and are not interchangeable in precise scientific work.
How accurate are these conversions?
Every conversion factor used here is the exact, internationally standardized value (e.g. 1 atm = exactly 101,325 Pa, and 1 psi = exactly 6,894.7572931783 Pa) — results are limited only by floating-point display precision, not by rounded conversion constants.