How to calculate conversion exchange fees? According to Exchange A, I can withdraw 1 BTC as 90 fiat. Or I can send them 1 fiat in return for 0.01 BTC. How do I calculate percentage fees for one way conversion?
The formula to calculate that is:
100% x (1-√(BTC x fiat))

where BTC and fiat are the two values highlighted in gray above.
Using the values given in the quesiton, it is 5.1%.
(Assuming that the conversion fees in both ways are calculated as a percentage, with the multiplier)