Core formulas: (1) Part = (Percent/100) × Whole. (2) Percent = (Part/Whole) × 100. (3) % Change = ((New − Old) / Old) × 100.
Percentages appear everywhere: discounts at checkout, salary changes, exam score improvements, and statistical comparisons.
The Percentage Calculator gives you a structured way to compute common percentage tasks—such as “what is X% of Y?”, “X is what % of Y?”, and “percentage increase/decrease”.
Because percentage math can be confusing when you mix base values, this tool uses clear inputs and provides the exact computation method.
For example, discounts require subtracting a percentage of the original price. Percentage change requires dividing the difference by the original value and multiplying by 100.
We also include worked examples so you can see the calculation in action—especially for cases where rounding matters.
Use the FAQ section for quick guidance on which formula applies to your scenario.
Example inputs and outputs using the calculator logic.
Quick links to similar calculators.
Answers to help you use the calculator correctly.
The whole is the base amount your percentage is taken from—e.g., original price before discount.
Discount amount = (percent/100)×original. Final price = original − discount.
Yes when converting a percentage to a multiplier. Percent/100 converts it into a factor.
Ensure you’re dividing by the original (old) value, not the new value.
For display, rounding to 2 decimals is common. For financial/legal uses, follow your required rounding rules.