Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Robert Kelly is managing director of XTS ...

Excel percentage formulas can get you through problems large and small every day—from determining sales tax (and tips) to calculating increases and decreases. We’ll walk through several examples below ...

An amount can be increased or decreased by a certain percentage to change its size. A reverse percentage problem involves finding the original amount before a percentage increase or decrease. The ...