Calculate percentages with multiple modes. Find what percentage one number is of another, calculate percentage change, increase or decrease values by percentage.
Basic: What is 25% of 200? = 50
Reverse: 30 is what % of 150? = 20%
Change: % change from 50 to 75 = 50% increase
Increase: Increase 100 by 10% = 110
Decrease: Decrease 100 by 10% = 90
A percentage calculator is a tool that performs various percentage-based calculations quickly and accurately. Percentages are used everywhere in daily life—from calculating discounts and tips to understanding statistics, financial data, and growth rates. A percentage calculator eliminates the mental math and potential errors, providing instant, accurate results for common percentage problems.
Our free Percentage Calculator offers six different calculation modes to handle all your percentage needs. Whether you need to find what percentage one number is of another, calculate percentage change, increase or decrease a value by a percentage, or convert decimals to percentages, our tool provides instant results with clear explanations.
While percentage calculations follow simple formulas, they're easy to get wrong when done manually, especially under time pressure or with large numbers. A percentage calculator ensures accuracy, saves time, and helps you understand the relationship between numbers. It's invaluable for shopping (calculating discounts), business (profit margins, growth rates), finance (interest rates, returns), academics (test scores, grades), and everyday decisions.
This basic percentage calculation finds a percentage of a number. For example, "What is 25% of 200?" The answer is 50. This is commonly used for calculating discounts (25% off $200 = $50 discount), tips (15% of $80 bill), taxes, and commission rates.
Formula: (X ÷ 100) × Y = Result
This reverse calculation determines what percentage one number represents of another. For example, "30 is what percent of 150?" The answer is 20%. Use this to calculate test scores (got 45 out of 50 = 90%), progress toward goals, market share, and conversion rates.
Formula: (X ÷ Y) × 100 = Result%
Calculate the percentage increase or decrease between two numbers. For example, the percentage change from 50 to 75 is a 50% increase. This is essential for analyzing growth rates, stock price changes, salary increases, population changes, and comparing year-over-year metrics.
Formula: ((New Value - Original Value) ÷ Original Value) × 100 = Result%
Add a percentage to a number. For example, increase 100 by 10% = 110. This is used for calculating price increases, adding sales tax, applying interest rates, and determining final prices after markup.
Formula: X + (X × (Y ÷ 100)) = Result
Subtract a percentage from a number. For example, decrease 100 by 10% = 90. Use this for calculating discounts, depreciation, price reductions, and finding net amounts after deductions.
Formula: X - (X × (Y ÷ 100)) = Result
Convert decimal numbers to percentages. For example, 0.75 = 75%. This is useful when working with statistics, probabilities, or mathematical results that need to be expressed as percentages.
Formula: Decimal × 100 = Percentage
The word "percent" comes from Latin "per centum" meaning "by the hundred." A percentage is simply a fraction with 100 as the denominator. For example, 25% means 25/100 or 0.25 as a decimal. Percentages make it easy to compare proportions because they're always on a scale of 0 to 100.
Key concepts:
A shirt costs $60 and is on sale for 30% off. How much do you save and pay?
Your salary is $50,000 and you get a 5% raise. What's your new salary?
You got 42 questions correct out of 50. What's your percentage score?
A stock was $100 and is now $125. What's the percentage gain?
Our percentage calculator:
Percentage is a fraction of 100 (e.g., 75% = 75/100). Percentile is a value below which a certain percentage of data falls (e.g., 75th percentile means 75% of values are below this point).
Because the base changes. If you start with 100, increase by 50% (=150), then decrease 50% of 150 (=75), you end at 75, not 100. The 50% decrease uses the new value (150) as its base.
Yes! Percentages over 100% simply mean more than the whole. For example, 200% of 50 = 100, or a 150% increase means the value increased by one and a half times.
Percentage change uses one value as the base (original). Percentage difference uses the average of both values as the base. Our calculator computes percentage change.
Use "What is X% of Y" with 15 and your bill amount. Or quick mental math: find 10% (move decimal left), then add half of that for the remaining 5%.