Exactly 85 °F is equal to 29.44 °C The conversion formula is Celsius temperature = 5/9 x (Fahrenheit temperature - 32) Start by taking the number in Fahrenheit and subtr … acting 32.Then multiply the number by 5, and then divide by 9. 85 - 32 = 53 53 x 5 = 265 265 / 9 = about 29.44 It is about 29.44.o convert from degrees Fahrenheit to degrees Celsius, subtract 32, multiply by 5, and divide by 9. In this instance:    85 - 32 = 53 x 5 = 265 / 9 = 29.4 recurring (th … at is, 29.4444..)    Therefore, 85 degrees Fahrenheit is equal to 29.4 recurring degrees Celsius. 8 people found this useful.