💯 Percentage Calculator
Quickly calculate percentages with four different calculation modes. Results update in real-time.
What is X% of Y?
X is what % of Y?
Percentage Change
Increase/Decrease by %
📖 Percentage?
A percentage is a way of expressing a number as a fraction of 100. The word "percent" comes from the Latin "per centum" meaning "by the hundred." Percentages are used everywhere in daily life: discounts while shopping, interest rates on loans, exam scores, tax rates, tips at restaurants, and statistical data.
Our percentage calculator provides four common calculation modes: finding X% of a number, determining what percentage one number is of another, calculating percentage change between two values, and increasing or decreasing a number by a percentage.
📝 Percentage Formulas
- X% of Y = Y × (X ÷ 100)
- X is what % of Y = (X ÷ Y) × 100
- % change from X to Y = ((Y − X) ÷ |X|) × 100
- X increased by Y% = X × (1 + Y ÷ 100)
❓ Frequently Asked Questions
To find X% of Y: multiply Y by X, then divide by 100. For example, 20% of 150 = 150 × 20 ÷ 100 = 30. You can also move the decimal point two places to the left: 20% = 0.20, then 150 × 0.20 = 30.
Percentage change = ((New Value - Old Value) ÷ Old Value) × 100. A positive result means increase, negative means decrease. For example, if a price goes from $80 to $100: ((100-80)÷80) × 100 = 25% increase.
A percentage is a fraction of 100 (e.g., 75% means 75 out of 100). A percentile indicates the relative standing of a value within a dataset (e.g., the 90th percentile means your score is higher than 90% of other values in the set).
📖 What Is a Percentage Calculator?
A percentage calculator performs common percentage operations quickly and accurately: finding what percentage one number is of another, calculating percentage increase/decrease, and determining the value of a percentage of a number. These calculations are used daily in finance, shopping (discounts), grades, statistics, and business metrics.
Our calculator provides instant results with step-by-step explanations, helping you understand the math behind the numbers. All calculations run locally in your browser.
🚀 How to Use This Tool
- Enter your numbers in the appropriate fields
- Select the type of percentage calculation
- View the instant result with formula breakdown
- Use the result for financial planning, grades, or statistics
💡 Tips & Best Practices
Quick Math: To find 15% of any number, calculate 10% (move decimal left) + 5% (half of 10%). Percentage change = ((New - Old) / Old) × 100. A 50% decrease followed by a 50% increase does NOT return to the original value.