Percentage Calculator
Calculate percentages quickly: find what percent of a number is, what percentage one number is of another, or the percentage change between two values.
What is this percent of the value below?
The base value to calculate the percentage of.
X is what percent of Y?
The base number for the "what percent" calculation.
The original value for percentage change.
The new value for percentage change.
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." Percentage calculations are used everywhere in daily life, from shopping discounts and tax calculations to investment returns and exam scores.
This calculator handles three of the most common percentage operations:
- What is X% of Y? Multiply Y by X/100. For example, 25% of 200 = 200 x 0.25 = 50.
- X is what percent of Y? Divide X by Y and multiply by 100. For example, 50 is what percent of 200? Answer: (50/200) x 100 = 25%.
- Percentage change: Subtract the old value from the new value, divide by the absolute value of the old value, and multiply by 100. For example, from 100 to 150: ((150-100)/100) x 100 = 50% increase.
Common Uses of Percentage Calculations
Percentages are fundamental to financial literacy and everyday math:
- Shopping: A 30% off sale on a $80 item saves you $24, making the price $56.
- Taxes: If sales tax is 8.5%, an item priced at $50 costs $54.25 after tax.
- Investments: Knowing that your portfolio grew 12% this year tells you more than saying it increased by a specific dollar amount, because the percentage accounts for the starting balance.
- Grades: Scoring 42 out of 50 on a test means you got 84%.
- Tips: A 20% tip on a $45 dinner is $9.
Understanding percentages also helps you evaluate claims in the news and advertising. "50% more" and "twice as much" are very different, and percentage points are not the same as percentages. A rate going from 2% to 3% is a 1 percentage point increase but a 50% relative increase.
Percentage Change vs. Percentage Point Difference
One of the most common sources of confusion with percentages is the difference between percentage change and percentage point change.
Percentage point change is the simple arithmetic difference between two percentages. If an interest rate goes from 3% to 5%, the change is 2 percentage points.
Percentage change expresses the change relative to the original value. Going from 3% to 5% is a 2 percentage point increase, but it represents a 66.7% relative increase (because 2/3 = 0.667).
This distinction matters in practice. If a politician says unemployment "dropped by 50%," that could mean it went from 6% to 3% (a 3 percentage point drop) or from 2% to 1% (a 1 percentage point drop). Both are a 50% decrease in the rate, but they describe very different labor market conditions.