How Percentages Work
A percentage is a ratio expressed as a fraction of 100. Use the tabs above for the four most common percentage calculations: finding X% of a number, finding what percent one number is of another, calculating percentage change, and increasing/decreasing a value by a percent.
Frequently Asked Questions
Percentage change = (New - Old) / Old x 100. If sales went from $80 to $100, the change is (100-80)/80 x 100 = 25% increase. If they went from $100 to $80, it is (80-100)/100 x 100 = -20% decrease.
A 50% loss on $100 leaves $50. A 50% gain on $50 gives only $75, not $100. You need a 100% gain to recover from a 50% loss. This asymmetry is why avoiding large losses matters more than chasing large gains.