Excel Math and Percentage Formulas

Math formulas cover the calculations behind budgets, reports and grade sheets: percentages, growth, averages, rounding and financial figures such as interest and present value.

Most percentage mistakes come from the order of operations or from formatting. A percent change is (new − old) / old, and a cell formatted as a percentage multiplies what it shows by 100. Rounding is similar: formatting hides decimals, but only ROUND, ROUNDUP and ROUNDDOWN change the stored value used in later calculations.

These tutorials cover percentages, rounding and decimals, averages, medians, percentiles and ranks, growth rates, and financial formulas such as compound interest, NPV and depreciation.