Free Tool

    Percentage Calculator

    Calculate percentages, percent increase/decrease, and percentage of numbers instantly with step-by-step explanations

    Calculate Percentages

    Choose a calculation type and enter your values

    Example: What is 20% of 100? Answer: 20

    What is a Percentage?

    A percentage is a number or ratio expressed as a fraction of 100. The word "percent" comes from the Latin "per centum," meaning "by the hundred." Percentages are used to express how large or small one quantity is relative to another.

    The percentage symbol (%) is used after the number to indicate it's a percentage. For example, 50% means 50 out of 100, or 50/100, which equals 0.5 as a decimal.

    Percentages are commonly used in everyday life for discounts, tax rates, interest rates, statistics, grades, and many other applications.

    How to Calculate Percentages

    Finding X% of Y:

    Multiply Y by X/100

    Example: 20% of 100 = 100 × (20/100) = 20

    Finding what % X is of Y:

    Divide X by Y and multiply by 100

    Example: 25 is what % of 200? (25/200) × 100 = 12.5%

    Percentage Change:

    ((New - Old) / Old) × 100

    Example: From 50 to 75: ((75-50)/50) × 100 = 50% increase

    Common Percentage Uses

    • Shopping & Discounts: Calculate sale prices and savings (e.g., 25% off $80 = $60)
    • Tips & Gratuity: Calculate restaurant tips (e.g., 18% tip on $50 bill = $9)
    • Finance & Banking: Calculate interest rates, loan payments, and investment returns
    • Academic Grades: Convert test scores to percentages (e.g., 45/50 = 90%)
    • Business & Analytics: Calculate growth rates, profit margins, and performance metrics
    • Taxes: Calculate sales tax and income tax amounts

    Percentage Tips & Tricks

    Quick Mental Math:

    10% of any number: Just move the decimal point one place left (10% of 250 = 25)

    Find 5%:

    Calculate 10% then divide by 2 (5% of 80 = 10% of 80 ÷ 2 = 8 ÷ 2 = 4)

    Find 15%:

    Add 10% + 5% (15% of 60 = 6 + 3 = 9)

    Reverse Percentage:

    X% of Y = Y% of X (20% of 50 = 50% of 20 = 10)

    Common Conversions:

    25% = 1/4, 50% = 1/2, 75% = 3/4, 33.33% = 1/3

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