Tipout formula based on server sales

I am trying to figure out a way to create a tip-out sheet for my restaurant something in the lines along;

Date    Bar Sales    Food Sales   Total Sales   Credit card payment    Cash payment   Credit card Tips  server owes/owe to server

then to break down what the server made in tips and create a formula for the tip out process for tip out pool - Bar 5% Buss/Run 15% Host 3%

Thanks!