๐ฏ Percentage Calculator
Calculate percentages instantly with three different modes. Real-time results as you type.
Example: What is 15% of 200? Answer: 30
Example: 30 is what % of 200? Answer: 15%
Example: From 50 to 75 = 50% increase
How to Use the Percentage Calculator
Our Percentage Calculator offers three distinct calculation modes, making it the most versatile percentage tool you'll find online. Each mode solves a different type of percentage problem, and all calculations happen in real time as you type โ no need to click any buttons.
Mode 1: What is X% of Y?
Use this mode when you need to find a specific percentage of a number. For example, calculating a 20% tip on a $85 bill, finding 15% off a sale price, or determining how much 8.5% sales tax adds to a purchase. Simply enter the percentage and the number, and the result appears instantly.
Mode 2: X is What % of Y?
This mode helps you determine what percentage one number represents of another. It's perfect for calculating test scores (e.g., "I got 42 out of 50 โ what's my percentage?"), determining what fraction of a budget has been spent, or figuring out completion rates. Enter both numbers and see the percentage immediately.
Mode 3: Percentage Change
The percentage change calculator shows how much a value has increased or decreased between two points. Enter the original (starting) value and the new (ending) value to see the exact percentage change. The calculator clearly indicates whether the change is an increase or decrease, shows the absolute difference, and provides the ratio between the two values. This is ideal for tracking price changes, salary comparisons, performance metrics, and investment returns.
Switch between modes using the tabs at the top of the calculator. Each mode remembers your inputs, so you can switch back and forth without losing your data.
About Percentage Calculations
Percentages are one of the most commonly used mathematical concepts in daily life. The word "percent" comes from the Latin "per centum," meaning "by the hundred." A percentage represents a fraction of 100, making it an intuitive way to express proportions, ratios, and changes.
The Basic Formula
The fundamental percentage formula is: Percentage = (Part รท Whole) ร 100. From this single formula, all three calculator modes are derived. To find "X% of Y," multiply Y by X/100. To find "X is what % of Y," divide X by Y and multiply by 100. Percentage change uses the formula: ((New โ Old) รท Old) ร 100.
Common Uses of Percentages
Percentages appear everywhere in modern life. In finance, they're used for interest rates, investment returns, tax rates, and discounts. In education, test scores and GPAs are based on percentage calculations. In health, body fat percentage, daily nutrient values, and medication dosages use percentages. In business, profit margins, market share, growth rates, and conversion rates are all expressed as percentages.
Understanding Percentage Change
Percentage change is particularly important because it provides context that raw numbers cannot. A $10 price increase means very different things for a $20 item (50% increase) versus a $1,000 item (1% increase). Always calculate percentage change from the original value to maintain mathematical accuracy. Note that percentage increases and decreases are not symmetrical โ a 50% increase followed by a 50% decrease does not return to the original value.
Frequently Asked Questions
To find X% of Y, multiply Y by X and divide by 100. For example, 15% of 200 = 200 ร 15 รท 100 = 30. Use our "What is X% of Y?" tab for instant results.
Percentage change = ((New Value โ Old Value) รท Old Value) ร 100. If the result is positive, it's an increase; if negative, it's a decrease. For example, going from 50 to 75 is a ((75โ50) รท 50) ร 100 = 50% increase.
A percentage is a mathematical value out of 100 (e.g., scoring 85% on a test). A percentile indicates rank relative to others (e.g., being in the 85th percentile means you scored higher than 85% of test takers). They measure different things entirely.
Yes! All three modes of our percentage calculator support decimal numbers. You can enter values like 7.5%, 12.25%, or 33.33% for precise calculations. The results will also show decimal precision when applicable.
Because percentages are relative to the current value. If 100 increases by 50%, it becomes 150. Then decreasing 150 by 50% gives 75, not 100. The decrease is calculated on the larger number (150), so it subtracts more than was originally added.