Calculate percentages, percentage change, and what percent one number is of another. Find sales discounts, marks, margins, and tips instantly with standard math formulas.
Calculating percentages is a fundamental math skill used daily in calculating tips, taxes, sales markdowns, and interest rates. Our free online Percentage Calculator helps you solve percentages easily in three different ways: finding what a specific percentage of a number is, calculating what percent one number is of another, and finding the percentage change between two values.
The basic percentage formula is Percentage = (Part / Whole) × 100. When calculating percentage change, the formula is Percentage Change = ((New Value - Original Value) / Original Value) × 100. This tool performs these operations in real time with high accuracy, ensuring reliable results for academic or professional use.
To calculate a percentage manually, divide the part by the whole, and then multiply the result by 100. For example, if you want to find what percentage 20 is of 80, divide 20 by 80 to get 0.25, and multiply by 100 to get 25%.
The percentage increase formula is: ((New Value - Original Value) / Original Value) * 100. Subtract the original value from the new value, divide by the original value, and multiply the result by 100.
To add a percentage to a number, multiply the number by (1 + percentage/100). For example, to add 15% to 80, multiply 80 by 1.15 to get 92.
20% off of 100 is 80. You calculate this by multiplying 100 by 0.20 to get 20, and then subtracting 20 from 100.