We use cookies to remember preferences and (with your permission) to measure performance. Learn more in our Privacy Policy.

    Skip to main content
    ToolsHub

    Percentage CalculatorFree Online Calculator Tool

    Percentage Calculator is a free online calculator tool. Calculate percentages, percentage change, and what percentage one number is of another. Free online percentage calculator with instant results.

    Calculate what a certain percentage of a number is.

    100% Private100% Private
    InstantInstant
    Any DeviceAny Device
    Free ForeverFree Forever
    How to useHow to use & Tips

    Steps

    1. 1Select the type of calculation you need: % of Number, % Change, or What %?
    2. 2Enter your numbers in the input fields
    3. 3Click 'Calculate' to see the instant result
    4. 4Use 'Reset All' to clear all fields and start a new calculation

    Use Cases

    • -Calculate discounts and final sale prices when shopping
    • -Determine tip amounts at restaurants
    • -Track investment gains or losses as a percentage
    • -Calculate grades and test score percentages
    • -Compute tax amounts on purchases
    • -Determine the percentage increase or decrease in metrics

    About Percentage Calculator

    Everything you need to know about this tool and how to get the most out of it.

    What is Percentage Calculator?

    What is Percentage Calculator?

    The Percentage Calculator is a free online tool that solves three of the most common percentage problems instantly: calculating what a percentage of a number is, finding the percentage change between two values, and determining what percentage one number is of another. It covers every everyday percentage scenario — from calculating a restaurant tip or a store discount to tracking investment performance or computing exam scores. All three calculation modes are available in one place, with results shown immediately as you click Calculate.
    How Percentage Calculator Works

    How Percentage Calculator Works

    The tool uses straightforward mathematical formulas for each mode. For '% of Number': result = (percentage / 100) × number. For '% Change': change = ((new - original) / original) × 100, with a positive result indicating an increase and a negative result indicating a decrease. For 'What %?': result = (part / whole) × 100. All computations run instantly in your browser using JavaScript — no server requests are made and no data is transmitted anywhere.
    Why Use Percentage Calculator?

    Why Use Percentage Calculator?

    Percentage calculations appear constantly in daily life: shopping discounts, sales tax, tips, investment returns, grade calculations, budget tracking, and more. While the math is not complex, it is easy to make errors when doing it mentally or with a basic calculator. This tool eliminates those errors by clearly labeling each input, showing the formula in context, and displaying results with two decimal places for precision. It is especially useful when you need to switch between different types of percentage calculations quickly.
    Tips

    Tips & Best Practices

    • 1Use the % Change tab to verify if a sale price is actually a good deal — enter the original and sale price
    • 2To calculate tax on a purchase: use '% of Number' with the tax rate and item price
    • 3To find what grade percentage you got: use 'What %?' with your score as part and total marks as whole
    • 4Percentage change can be negative — that's a decrease in value
    • 5For compound calculations, chain multiple uses of the tool together
    • 6Reset All clears every tab at once so you can start fresh quickly
    Percentage Formulas Reference

    Percentage Formulas Reference

    Three core formulas cover nearly every percentage scenario. (1) Percentage of a Number: Result = (P/100) × N, where P is the percentage and N is the number. Example: 15% of 80 = 12. (2) Percentage Change: Change% = ((New - Old) / Old) × 100. Positive = increase, negative = decrease. Example: from 50 to 60 = +20%. (3) What Percentage?: Result = (Part / Whole) × 100. Example: 30 is what % of 120? = 25%. These three formulas handle discounts, growth rates, exam scores, tips, taxes, and most other everyday percentage needs.
    Common Percentage Calculation Mistakes

    Common Percentage Calculation Mistakes

    The most frequent mistake is confusing 'percentage of' with 'percentage change'. For example, a price going from $100 to $120 is a 20% increase (percentage change), but $120 is 120% of $100 (percentage of). Another common error is dividing in the wrong direction — when calculating what percent A is of B, always divide A by B, not B by A. Also note that percentage points and percentages are different: if interest rates go from 2% to 3%, that is a 1 percentage point increase but a 50% increase in the rate itself.

    Frequently Asked Questions