kPa to ATM Conversion Calculator — Kilopascals to Atmospheres
Convert kilopascals (kPa) to standard atmospheres (atm) and other common pressure units. 1 standard atmosphere = 101.325 kPa exactly, so 1 kPa ≈ 0.009869 atm. Enter any kPa value to get atm, bar, psi, mmHg and Pa instantly.
kPa
1 kPa = 1000 Pa / 101,325 Pa per atm ≈ 0.009869 atm
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Convert kPa to Pascals
101.325 × 1,000 = 101,325 - 2
Divide by Pa per atm
101,325 ÷ 101,325 = 11 atm is defined as exactly 101,325 Pa.
How does this calculator work?
1 kPa = 0.009869 atm = 1000 Pa = 0.01 bar = 0.14504 psi = 7.5006 mmHg. The key reference: 101.325 kPa = 1 atm exactly. Multiply kPa by 0.009869 to get atm; multiply atm by 101.325 to get kPa. The calculator also outputs Pa, bar, psi and mmHg from a single kPa input.
Formula
How this is calculated
The kilopascal (kPa) is the SI-derived pressure unit equal to exactly 1000 pascals (Pa). The standard atmosphere (atm) is defined as exactly 101,325 Pa = 101.325 kPa — it approximates the mean sea-level atmospheric pressure adopted as the International Standard Atmosphere. To convert kPa to atm, multiply by 1000 to get Pa, then divide by 101,325; this simplifies to multiplying by 1/101.325 ≈ 0.009869. The inverse is atm × 101.325 = kPa, an exact relationship.
In practice, pressure readings from tyre gauges, vacuum pumps, weather stations, and medical instruments often come in kPa, while chemistry and thermodynamics problems (gas law problems, solubility, equilibrium) frequently specify atmospheres. The related bar unit (1 bar = 100 kPa = 0.986923 atm) has largely replaced atm as the thermodynamic standard state since 1982 (IUPAC), but both units remain in widespread use.
Note on gauge vs. absolute pressure: many instruments display gauge pressure — the pressure above ambient atmospheric — rather than absolute pressure. At sea level, gauge kPa + 101.325 kPa ≈ absolute kPa. Always check which convention your instrument uses before converting.
Frequently asked questions
100 kPa = 100,000 Pa / 101,325 Pa per atm ≈ 0.9869 atm. This is also equal to exactly 1 bar, since 1 bar = 100,000 Pa = 100 kPa. Standard atmospheric pressure (1 atm) is slightly higher at 101.325 kPa.
Yes. The standard atmosphere is defined as exactly 101,325 Pa = 101.325 kPa. This is a defined constant, not a measured value, so 101.325 kPa = 1.000000 atm to any number of decimal places.
Use atm for chemistry gas law problems, scuba diving depth calculations, and comparison with older thermodynamic tables. Use kPa in SI-based engineering, meteorology (weather maps use hPa = 0.1 kPa), and medical contexts. In the US, psi dominates for tyres and industrial pressures.
Also known as
TG we-Calculate Editorial Team. (2026). kPa to ATM Conversion Calculator — Kilopascals to Atmospheres [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/kpa-to-atm-conversion-calculator
TG we-Calculate Editorial Team. "kPa to ATM Conversion Calculator — Kilopascals to Atmospheres." TG we-Calculate. 2026. https://we-calculate.com/calculator/kpa-to-atm-conversion-calculator.
TG we-Calculate Editorial Team, "kPa to ATM Conversion Calculator — Kilopascals to Atmospheres," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/kpa-to-atm-conversion-calculator
@misc{wecalculate_kpa_to_atm_conversion_calculator, title = {kPa to ATM Conversion Calculator — Kilopascals to Atmospheres}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/kpa-to-atm-conversion-calculator}}, year = {2026}, note = {TG we-Calculate} }
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