Nice post . Gonna hit that gym hard today ! <| sep |> The DB maybe rejects your credit card because it has no EMV Chip , German standard . A safety for DB against fraud , they mean it seriously with it . Also it could be you have to unlock international payments manually by calling your Bank . <| sep |> Suddenly a couple million people show up armed to parliament . LOL . UK . You need to grow some balls . <| sep |> The formula is justdifference originalSo A compared to B is A B Band B compared to A is B A ASo if A 10 and B 8 we get 10 8 8 2 8 0 . 25 So A is 25 % more than B , and 8 10 10 2 10 0 . 2 So B is 20 % less than A . There are other ways to get the same results , but difference original will always give you the correct answer so it ' s what you should use unless you need to do some crazy algorithm optimization .