🔢 Percentage Calculator
Three calculators in one — instant percentage results.
How to Use This Percentage Calculator
This tool offers three percentage calculation modes that cover the most common scenarios:
- What is X% of Y? — Find a percentage of any number (e.g., "What is 15% of 200?" → 30)
- X is what % of Y? — Determine what percentage one number is of another (e.g., "25 is what % of 200?" → 12.5%)
- % Change from X to Y — Calculate the percentage increase or decrease between two values (e.g., "From 80 to 100" → +25%)
Percentage Formulas
- X% of Y = (X / 100) × Y
- X is what % of Y = (X / Y) × 100
- % Change = ((New − Old) / |Old|) × 100
Common Use Cases
Percentages come up everywhere: calculating discounts while shopping, figuring out tips at restaurants, analyzing test scores, tracking investment returns, or computing tax amounts.
Speed up your daily work with keyboard shortcuts that save hours every week.
What Is a Percentage Calculator?
A percentage calculator is an essential math utility that solves the three most common percentage problems: finding what X% of a number equals, determining what percentage one number is of another, and calculating the percentage change between two values. Our tool provides instant results with the formula shown, making it useful for students, shoppers calculating discounts, investors tracking returns, and professionals analyzing data — all without needing a physical calculator or spreadsheet.
How to Use This Tool
- Choose your calculation type — Click one of the three tabs: "What is X% of Y?" for finding a percentage of a number, "X is what % of Y?" for determining proportions, or "% Change" for comparing two values over time.
- Enter your numbers — Type your values into the input fields. Results calculate automatically as you type — no submit button needed.
- Read the result and formula — The answer appears in large text, with the complete formula shown below for verification or learning purposes.
Why Use Our Percentage Calculator?
- Three calculators in one — Covers all common percentage problems without switching between tools or pages.
- Shows the formula — Helps students understand the math behind each calculation, not just the answer.
- High precision — Displays up to 10 decimal places for exact results when needed.
- Color-coded change — Percentage increases show in green, decreases in red, making trends instantly clear.
Frequently Asked Questions
How do I calculate a discount?
Use "What is X% of Y?" — enter the discount percentage and original price. For example, "What is 25% of 80?" gives you $20 off, meaning the final price is $60.
How do I find the percentage increase between two numbers?
Use the "% Change" tab. Enter the original value in "From" and the new value in "To." The tool calculates ((New − Old) ÷ |Old|) × 100 automatically. A positive result means an increase, negative means a decrease.
Why does my percentage change show as negative?
A negative percentage change means the value decreased from the first number to the second. For example, going from 100 to 75 is a −25% change because the value dropped by a quarter.