Question: how to calculate percentage delta between two numbers?
Answer: A relative delta compares the difference between two numbers, A and B, as a percentage of one of the numbers. The basic formula is A - B/A x100. For example, if you make $10,000 a year and donate $500 to charity, the relative delta in your salary is 10,000 - 500/10,000 x 100 = 95%.