If you're quick at math here's a fairly accurate way:
F->C: Subtract 30, divide by 2.
C->F: Double it & Add 30.
Often known as the "Bob & Doug McKenzie method" from around here it makes for fast conversions since the actual conversion (°F - 32) * 5 / 9 = °C is close enough when dealing in the normal temperature range of weather.
That's really interesting and something I will have to remember.
My friend is from the UK so when we talk about temps (they don't get the winter we get in my area of the US) I try to convert it.
I've been counting along increments of 1.5 in whichever direction from 0 C or 32 F.
I probably made it a .5 for mental calculating.
Just out of curiosity I tried yours and it even works with minus temperatures, although a bit confusing at first.
Yours are exactly the reason I read the comments on posts.
