Banquets gratuity Sheet

I am wanting to create a excel spreadsheet that shows the name of the event, BEO #, Spot of total food grat and total bar grat, space for me to add up to 15 servers names as well as 5 servers names. I want a spot that shows what the gratuity for the servers is and the bartenders and then a spot that has how many hours they worked. So when I plug in how many hours they worked it will automatically calculate their gratuity. The gratuity is 15%.