This calculator uses Newton's Law of Cooling. Enter all but one field. The script will calculate the last field. If you do not know your coefficient constant, you can calculate it based on a known cooling event. To calculate your coefficient you will need: initial temp of wort, final temp of wort, time in the coolship, and average ambient temp for that time period. Plug those in and you can calculate your coefficient. Benefits thereafter are: #1 calculating time your wort sits within temp ranges and #2 estimate how long it will take to cool down to X temperature. For 5.5 gallons of wort in an 8 gallon stainless steel pot (12.5" diameter), we came up with a coefficient constant of 0.244157. If your equipment is similar, your number should come up close. Use °C or °F, but not both.