I guess the formula you should have posted is Dolbear's Law Temp (F) = 50 + ([Chirps per minute -40] /4) Temp (F) = 50 + ([20 -40]/4) Temp (F) = 50 + (-20 / 4) The temperature in degrees Fahrenheit is 45 degrees (do crickets even chirp at this temperature?) Source: https://en.wikipedia.org/wiki/Dolbear%27s_law