Cloud Base Height Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 28, 2026Cloud Base Height Calculator
Estimate cloud ceiling height using a standard aviation rule of thumb based on surface temperature and dew point.
Cloud Base (ft) = (Surface Temp - Dew Point) x 227
Example
75┬░F surface temperature, 60┬░F dew point:
Spread = 15┬░F → ~3,405 feet above ground level
Why the Temperature-Dew Point Spread Matters
This estimate uses the temperature-dew point "spread" method, a common aviation weather rule of thumb - a smaller spread between surface temperature and dew point indicates a lower cloud base, since rising air only needs to cool a small amount before reaching saturation and condensing into visible cloud.
Why Pilots Rely on This Quick Estimate
This quick mental-math estimate gives pilots a useful first approximation of cloud ceiling before checking official aviation weather reports (METARs/TAFs) - it's derived from the standard atmospheric lapse rate and remains a widely taught rule of thumb in pilot training.