About Delisle to Fahrenheit Conversion Conversion Formula The formula to convert from Delisle (°De) to Fahrenheit (°F) is: °F = 212 - (°De × 6/5) Key Reference Points Water Boiling Point: 0°De = 212°F Water Freezing Point: 150°De = 32°F Absolute Zero: 559.725°De = -459.67°F