Percentage Calculator

Three ways to calculate percentages. Pick a mode and get your answer instantly.

What is % of ?
Result
50
From to
Percentage Change
+25%
is what % of ?
Percentage
25%
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How to Calculate Percentages

A percentage is a way of expressing a number as a fraction of 100. The word "percent" literally means "per hundred." The three most common percentage calculations are: finding what percentage one number is of another, finding a percentage of a number, and finding the whole when you know a part and a percentage.

What is X% of Y? → (X / 100) x Y
X is what % of Y? → (X / Y) x 100
X is Y% of what? → X / (Y / 100)

How to Use This Calculator

This calculator solves all three types of percentage problems. Enter any two values and it instantly calculates the third. You can also calculate percentage change (how much a value increased or decreased as a percentage), percentage difference between two numbers, and add or subtract a percentage from a number. Each calculation type has its own section with clear labels.

Common Percentage Calculations

Tips: A 20% tip on a $50 bill is $10. Calculate it as $50 x 0.20 = $10. The Tip Calculator handles this with bill splitting. Discounts: 30% off a $80 item saves $24, making the sale price $56. The Discount Calculator shows savings instantly. Tax: 8.25% sales tax on $100 adds $8.25. The Sales Tax Calculator handles state-specific rates. Grades: Scoring 42 out of 50 is 84%. The Grade Calculator handles weighted grades.

Percentage Change Formula

Percentage change measures how much a value has increased or decreased relative to its original value. The formula is: Percentage Change = ((New Value - Old Value) / Old Value) x 100. A positive result means an increase; a negative result means a decrease. For example, if a stock price goes from $50 to $65, the percentage change is ((65 - 50) / 50) x 100 = 30% increase.

Percentage Calculator FAQ

How do I convert a fraction to a percentage?
Divide the numerator by the denominator, then multiply by 100. For example, 3/4 = 0.75 x 100 = 75%. The Fraction Calculator can handle fraction-to-decimal conversions.
How do I convert a decimal to a percentage?
Multiply by 100 and add the percent sign. For example, 0.85 = 85%. Conversely, to convert a percentage to a decimal, divide by 100. So 85% = 0.85.
What is the difference between percentage change and percentage difference?
Percentage change measures the change relative to the original value (useful when comparing before and after). Percentage difference measures the difference relative to the average of two values (useful when neither value is clearly the "original"). Use percentage change for time-based comparisons and percentage difference for side-by-side comparisons.