Growing Degree Days Calculator

Units

Mode

Base temperature

Apply the 86/50 capBefore averaging, cap the high at 86°F and raise the low to at least 50°F. See “Why the 86/50 Cap Exists” below.

High temperature (°F)

Low temperature (°F)

The math:

GDD = ((Tmax + Tmin) ÷ 2) − Tbase

Negative results count as zero, since development doesn’t run backward.

((75 + 55) ÷ 2) − 50 = 15 GDD

Growing degree days for this day

15 GDD

Base 50°F · 86/50 cap on