Percentage Calculator

What is Percentage Calculator?

A percentage is a way of expressing a number as a fraction of 100, and it is one of the most widely used mathematical concepts in everyday life. Whether you are figuring out how much you save during a store sale, calculating the tip at a restaurant, determining your exam score, or understanding interest rates on a loan, percentages are everywhere. Students use percentages in math, science, and economics classes to express ratios and probabilities. Professionals in finance, marketing, and data analysis rely on percentage calculations daily to track growth rates, conversion rates, profit margins, and year-over-year changes. Even simple tasks like reading nutrition labels, comparing product prices per unit, or understanding election poll results require a solid grasp of percentages. Our free online percentage calculator handles all common percentage operations instantly: finding what percentage one number is of another, calculating a specific percentage of any number, and computing the percentage increase or decrease between two values. Because the entire calculation runs client-side in your browser, your data never leaves your device, making it completely private and lightning-fast with zero server delays.

How to Use

1. Choose the calculation type you need: 'What is X% of Y?', 'X is what % of Y?', or 'Percentage change from X to Y'. Each mode is optimized for the most common real-world percentage questions.
2. Enter your values into the input fields. You can type whole numbers, decimals, or negative numbers. The calculator accepts values of any size, so it works for everything from simple homework problems to large financial figures.
3. Read the result instantly -- the answer updates in real time as you type, with no need to press a calculate button. The result is displayed with up to two decimal places for precision.
4. Use the copy button to paste the result into a spreadsheet, document, or another calculator. You can also clear the fields and run a new calculation immediately.
5. For percentage change calculations, pay attention to the sign of the result: a positive value means an increase, while a negative value means a decrease. This is especially useful for tracking stock prices, sales performance, or weight change over time.
6. Pro tip: bookmark this page for quick access whenever you need a percentage calculation. It works offline once loaded, so you can use it on planes, in classrooms, or anywhere without an internet connection.

Formula

Frequently Asked Questions

How to calculate 20% off a price?

To calculate 20% off, multiply the original price by 0.20 to find the discount amount, then subtract it from the original price. For example, 20% off $85: discount = $85 x 0.20 = $17, so the sale price is $85 - $17 = $68. A shortcut is to multiply the price by 0.80 (which is 1 minus 0.20) to get the final price directly: $85 x 0.80 = $68.

What is the percentage change formula?

The percentage change formula is ((New Value - Old Value) / |Old Value|) x 100. Use the absolute value of the old value in the denominator. A positive result indicates an increase and a negative result indicates a decrease. For example, if your rent goes from $1,200 to $1,350, the change is ((1350 - 1200) / 1200) x 100 = 12.5% increase. This formula is essential in finance, economics, and data analysis for measuring growth, inflation, and performance over time.

How to convert a fraction to a percentage?

Divide the numerator by the denominator, then multiply by 100. For example, 3/8 = 0.375 x 100 = 37.5%. For mixed numbers, first convert to an improper fraction: 2 and 1/4 = 9/4 = 2.25 x 100 = 225%. This works because a percentage literally means 'per hundred,' so you are expressing how many parts out of 100 your fraction represents.

How to calculate tax percentage?

To calculate the tax amount, multiply the pre-tax price by the tax rate as a decimal. For example, if sales tax is 8.25% and the item costs $49.99, the tax is $49.99 x 0.0825 = $4.12 (rounded), making the total $54.11. To reverse-engineer the tax rate from a receipt, subtract the pre-tax total from the after-tax total, divide by the pre-tax total, and multiply by 100. For instance, if pre-tax is $50 and after-tax is $54.25, the rate is (4.25 / 50) x 100 = 8.5%.

What is the difference between percentage point and percentage?

A percentage point is an absolute difference between two percentages, while a percentage is a relative measure. If an interest rate rises from 3% to 5%, it increased by 2 percentage points but increased by 66.7% in relative terms ((5 - 3) / 3 x 100). This distinction matters in finance and statistics -- news headlines often confuse the two, leading to misunderstandings about the magnitude of changes.

How to find what percentage one number is of another?

Use the formula: (Part / Whole) x 100. For example, if 35 students out of a class of 120 earned an A, then (35 / 120) x 100 = 29.17% of the class earned an A. This calculation is used everywhere: batting averages, market share, survey results, grade distributions, and more.

How to calculate percentage increase between two numbers?

Subtract the old value from the new value, divide by the old value, and multiply by 100. For example, if your salary went from $52,000 to $58,500: ((58500 - 52000) / 52000) x 100 = 12.5% increase. For percentage decrease, the same formula applies and gives a negative result. If a product price drops from $120 to $96: ((96 - 120) / 120) x 100 = -20%, meaning a 20% decrease.

Can percentages be greater than 100%?

Yes, percentages can exceed 100%. A 150% increase means the new value is 2.5 times the original. For example, if a company's revenue grows from $1 million to $2.5 million, that is a 150% increase. Percentages over 100% are common when measuring growth, returns on investment, or markups. A store that buys an item for $40 and sells it for $100 has a markup of 150%.