Free Online Percentage Calculator
This percentage calculator handles every common percentage problem instantly — what percent one number is of another, percentage increase and decrease, percent change, and discounts. Enter your numbers in the tool above and get the answer in real time.
How to Calculate a Percentage
To find what percentage one number is of another, divide the part by the whole and multiply by 100. For example, 16 out of 20 is (16 ÷ 20) × 100 = 80%.
Percentage Increase and Decrease
To find a percentage increase, subtract the old value from the new value, divide by the old value, and multiply by 100. For a percentage decrease, do the same with the drop in value. The calculator above does both automatically.
Percentage Off (Discounts)
To find a sale price, multiply the original price by the discount percentage, then subtract. A 25% discount on $80 is $80 × 0.25 = $20 off, so you pay $60.
Frequently Asked Questions
How do I calculate a percentage of a number?
Divide the part by the whole and multiply by 100. For example, 16 out of 20 = (16 ÷ 20) × 100 = 80%.
How do I calculate percentage increase?
Subtract the old value from the new value, divide by the old value, and multiply by 100.
How do I calculate a discount?
Multiply the original price by the discount percentage and subtract it from the price.