Can someone help settle a coworker and I's debate over how to convert a fee percentage to APR. Can it even be done since one takes into account time and extra fees and the other does not? For example, how would a 10% fixed fee on a one year 100k loan compare to a 10% interest rate on a 100k one year loan? Would it change things if the 100k with a flat fee was a daily payment and the 100k at 10% interest was monthly?