It is 0F in m y freezer but I want it twice as cold. How cold is that?
What is the ambient temperature outside the freezer? Any temperature change is relative, not absolute.
“Twice as cold” is typically not defined outside of a particular context. You can approach this with two reasonable guesses:
[ul]
[li]You can take your room temperature outside the freezer. Subtract the freezer temperature from it, and subtract that from your freezer temperature. For example, if your room is 65F, and your freezer is 0F, then this sort of “twice as cold” would be -65F. [/li][li]Another approach would be to convert your freezer temperature to Kelvin, halve it, convert back to Fahrenheit. For 0 F that would yield “twice as cold” to be about -230F[/li][/ul]