A friend said you were the guy for the job - open to bidding

Hello I'm looking for a web based calculator that a visitor will used by entering in various data that has some basic math preformed and outputs a value. The primary input will be: monthly sales in dollars (users will enter a whole number) and profit margin (entered as a % between 0-100) secondary inputs will be, for example: percentage of sales done as credit card transactions (entered as a percent using a slider that goes from 0%-100%) there will be a few more secondary inputs namely: %sales in debit, cash, bitcoin and other credit card, debit, and other will have the option of entering tertiary inputs. tertiary inputs will be, % cost per transaction (entered as a % between 0-100), cost per month (entered as a number with 2 decimal places), flat fee per transaction (entered as a number with 2 decimal places) the goal is to output a monthly cost savings. the math will look something like this. (monthly sales x profit margin) - [(% of sales in credit card transactions) x % cost per transaction] - [(% of credit card transactions) x flat fee per transaction] - monthly fee = credit card transaction fees per month 'debit' and 'other' transactions will have similar math preformed to get transaction fees per month cash and bitcoin transactions will have 0 fees sum of transactions fees = total monthly transaction fees find difference between total monthly transaction cost and total monthly transaction cos excluding bitcoin that difference is equal to monthly savings due to bitcoin integration. multiply monthly savings due to bitcoin integration by 12 to get yearly savings due to bitcoin integration. it must have a nice interface. it must work on mobile devices if possible id like it updated instantaneously without the need to hit a 'calculate' button every time an input is altered.