Percentage Calculator
Calculate percentages instantly: find X% of a number, determine what percent X is of Y, and view step-by-step formulas.
About the Percentage Calculator
Percentages are universal ratios expressed as a fraction of 100. Whether you are calculating sales tax, restaurant tips, exam grades, commission rates, or financial returns, percentages allow instant comparison across different totals.
Our Percentage Calculator solves the two most important everyday percentage questions: finding what X% of Y is, and determining what percent X is of Y.
Core Percentage Formulas
Use these three fundamental equations to solve any percentage problem:
Value = (P / 100) × YPercentage (%) = (X / Y) × 100%Total (Y) = X / (P / 100)How to Calculate Percentages Step-by-Step
- Convert the Percentage to a Decimal: Divide the percentage value by 100 (move the decimal point two places to the left).
- Multiply by the Total Amount: Multiply that decimal by the whole number to find the part.
- To Find What Percent X is of Y: Divide the part (X) by the whole (Y), then multiply the decimal result by 100.
Worked Example: To find 20% of 150, convert 20% to 0.20, then multiply: 0.20 × 150 = 30.
Frequently Asked Questions (FAQ)
What is the fastest mental math trick for percentages?
Percent is reversible! “X% of Y” is always equal to “Y% of X.” For example, 16% of 25 is the exact same as 25% (one-fourth) of 16, which is 4.
How do I calculate a 15% tip or discount quickly?
Find 10% by moving the decimal point one place to the left, then take half of that 10% amount to get 5%, and add them together.
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