Percentage Calculator
Solve every kind of percentage problem in seconds — no math headache required.
What is it?
A percentage calculator is a handy tool that helps you answer the four most common percentage questions: “What is X percent of a number?”, “X is what percent of Y?”, “By how much did a value increase or decrease?” and “What is the number before a percentage change?”. Our online percentage calculator bundles all of them in one clean interface. Fill in the fields you know and the tool computes the missing value instantly. Everything runs in your browser, so there is no waiting and no login — just fast, accurate results. It is perfect for shopping discounts, tax computations, grades, tips, commissions, sales funnels and basic statistics at work.
How to use it
- Pick the calculation you need: percent of a number, percent change, or finding the percentage.
- Enter the values you know in the two input fields.
- The result appears instantly next to the formula — no button to press.
- Switch the calculation type at any time to run a new scenario.
- Use the “Copy” button to grab the result for a spreadsheet, email or note.
Why use this tool
Percentages are everywhere: the 20% off on a new pair of sneakers, the 4% interest rate on a mortgage, the 30% commission on a sale, the 8% VAT on a receipt. Doing them by hand is easy to get wrong, especially when multiple values and rounding rules are involved. Our calculator shows the formula next to the answer, so you also learn how the result is obtained — useful for students and for quick sanity checks. Because it runs in your browser, it is instant, works offline once loaded, and never sends your numbers anywhere. No tracking, no tip jar, no newsletter pop-up. Use it at the cash register, while reviewing invoices, when planning an ad campaign or just to split a restaurant bill fairly.
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 20% of 80 is (80 × 20) / 100 = 16.
How do I calculate a percentage increase?
Subtract the original value from the new value, divide by the original value and multiply by 100. Our tool does the math automatically.
What is the formula for percentage decrease?
Subtract the new value from the original, divide by the original and multiply by 100. A negative result means an increase was entered as a decrease.
Does the calculator round results?
Results are displayed with up to six decimal digits and are not rounded internally, so you can rely on the exact value in scientific or financial contexts.
Can I calculate VAT with this tool?
Yes. Use the “percentage of a number” mode: enter the net price and your VAT rate to get the tax amount, or use percentage change between net and gross to verify a rate.