Create a list of the items or categories you need to include on the pie chart. For an example, use expenses in a household of $575 for rent, $70 for electric, $45 for heat and $25 for water.
Add all expenses together for a total of $715 in expenses for the month. Convert each number to a percent of the whole by dividing it by $715. Rent is 80.4 percent, electric is 9.8 percent, heat is 6.2 percent and water makes up 3.6 percent of your monthly expenses. Each section has a portion on the graph.
Combine the two expenses you want to overlap into a single category, such as electric and heat. The new total is $115 and makes up 16 percent of the monthly expenses. The new graph eliminates two separate categories for heat and electric and links them together in a new category.