Compute International Standard Atmosphere temperature and lapse rate by altitude.
由海拔高度按 ISA 模型求气温：对流层（≤11km）每千米降 6.5℃，平流层底部恒温。
| Item | Formula | Source / Standard |
|---|---|---|
| ISA temperature lapse rate | T = 288.15 - 0.0065 h (K, m) | ICAO International Standard Atmosphere |
| ISA pressure | p = 101325 (1 - 2.25577e-5 h)^5.25588 | ICAO International Standard Atmosphere |
| Tropopause altitude | at 11000 m temperature fixed at 216.65 K | ICAO International Standard Atmosphere |
Constants and standards used on this page with their authoritative sources, for verification and citation.
| Quantity | Value | Unit | Source |
|---|---|---|---|
| Sea-level standard temperature T₀ | 288.15 (= 15 °C) | K | ISO 2533:1975 Standard Atmosphere (same value in ICAO Doc 7488) |
| Sea-level standard pressure p₀ | 1013.25 (= 101325 Pa) | hPa | ISO 2533:1975; note: IUPAC standard pressure changed to 100 kPa in 1982 |
| Tropospheric lapse rate L | 6.5 (0.0065 K/m) | K/km | ISO 2533:1975 (0-11 km layer) |
| Tropopause height / temperature | 11 km / 216.65 K (-56.5 °C) | km / K | ISO 2533:1975 |
| Standard gravity g₀ | 9.80665 | m/s² | ISO 80000-3:2019 |
| Dry-air gas constant R_d | 287.05287 | J/(kg·K) | CIPM 2007 recommended value (dry air M = 28.96546 g/mol) |
| Pressure-ratio exponent 5.25588 | g₀/(R_d·L) = 5.25588 | dimensionless | Derived from the ISO 2533 tropospheric integration |
| Coefficient 2.25577×10⁻⁵ | L/T₀ = 2.2558×10⁻⁵ | m⁻¹ | Derived as L/T₀ (L = 0.0065 K/m, T₀ = 288.15 K) |
Note: ISA is a conventional reference atmosphere; the real atmosphere deviates with weather, season and latitude. Aviation altimeters require QNH correction; results here serve teaching and engineering estimates only.
工作与生活中的相关计算与查询。
国际标准大气（ISA）对流层温度 T=288.15−6.5·h（h 为海拔 km，单位 K），即每升高 1 km 约降 6.5℃。
结果可显示 K 或 ℃；公式仅适用于对流层（海拔 ≤ 11 km）。平流层（11–20 km）温度基本恒定约 216.65 K。
ISA 为平均标准模型；实际大气随纬度/季节/天气明显偏离，航空/气象请以实测为准。