How to Calculate Percentages

Percentages are simply fractions with a denominator of 100. The word "percent" literally translates to "per hundred." This calculator runs locally in your browser to instantly solve the three most common percentage problems encountered in finance, math, and daily life.

1. Finding the Percentage of a Number

If you need to find 20% of 150 (useful for calculating tips or discounts), convert the percentage to a decimal by dividing by 100, then multiply by the total.

2. Finding What Percentage One Number is of Another

If you scored 30 out of 150 on a test and want to know your percentage grade, divide the part by the whole and multiply by 100.

3. Calculating Percentage Change (Increase/Decrease)

This is commonly used in business to calculate profit margins or stock market growth. To find the percentage increase or decrease between two numbers, find the difference between them, divide by the original number, and multiply by 100.