The term "variance" in has a meaning in statistics that is different from its meaning in accounting. We assume here that you are interested in the accounting meaning, the difference between two numbers. Choose one number to be the reference, or base. In accounting, that is often the one occurring earlier in time, the budgeted amount (as opposed to the actual amount), or sales revenue (as opposed to cost of goods). Here, we'll call that the "old" amount. The other number will be called the "new" amount. Percent change = (new - old)/old*100% Example Last year's attendance at the event was 8,000 people. This year, attendance was 6,000 people. The percentage change is (6000 - 8000)/8000*100% = -2000/8000*100% = -25% Attendance was down 25% from last year.