Weather Correction Horsepower Calculator

Liguori Drag Racing • Weather

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Weather Correction Horsepower

Estimate naturally aspirated power at reference weather conditions.

Starting values are examples. Enter your measurements; results update as you type.

Method & assumptions

Use absolute station pressure from a weather station. A weather app’s sea-level pressure is not station pressure. Results describe the air at the entered conditions; they do not predict an engine tune. J1349-style correction: 1.18 × (990 / dry pressure in hPa) × √(K / 298.15) − 0.18. An estimate for naturally aspirated spark-ignition engines, not a boost-engine correction or certification.