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
