The only percentage tool you need. Calculate percentage increases, find parts of a whole, and solve ‘X is what percent of Y’ problems instantly.

History

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    How to Use

    Why this matters

    Percentages are the universal language of comparison. Whether you are calculating a discount at a store, analyzing stock market returns, or grading a test, understanding how to manipulate these numbers is essential.

    The Three Modes explained

    1. Percentage of a Number: Use this to find a portion. Example: “What is 20% of my $50 bill?”
    2. What % is X of Y: Use this to find the rate. Example: “I got 45 questions right out of 50. What is my grade?”
    3. Percentage Change: Use this to compare growth or loss. Example: “My rent went from $1,000 to $1,100. How much did it go up?”

    The Math Behind It

    Depending on the mode you selected, the tool uses one of these three formulas:

    $$ P = \frac{\%}{100} \cdot \text{Total} \quad \bigg| \quad \% = \frac{\text{Part}}{\text{Total}} \cdot 100 \quad \bigg| \quad \Delta\% = \frac{\text{New} - \text{Old}}{\text{Old}} \cdot 100 $$

    Where:

    • $P$ is the Part (the result).
    • $\Delta\%$ is the Change in percentage.
    • Values are standard decimal or integer inputs.