Percentage Calculator: Find Percent of a Number & Percent Change Instantly
Choose a calculation type: find a percentage of a number, express one number as a percent of another, or measure the percentage change between two values.
Calculated values are estimates for general information only and are not financial advice. Results may vary with rounding.
Stop doing percentage math in your head. Whether you need to find what percent 30 is of 150, calculate 15% of 200, or measure the percentage change from 80 to 100, this free tool gives you the exact answer in seconds.
✅ Quick Answer: What is the percentage?
15% of 200 = 30 (multiply 200 by 0.15). 30 is 20% of 150 (30 ÷ 150 × 100 = 20%). From 80 to 100 = 25% increase ((100 − 80) ÷ 80 × 100 = 25%).
Choose your mode below: "What is X% of Y", "X is what % of Y", or "Percentage change from A to B". Enter your numbers and get the result instantly.
Results are rounded to two decimal places.
Frequently Asked Questions
How do I calculate what percent one number is of another?
Divide the part by the whole and multiply by 100. For example, 30 ÷ 150 × 100 = 20%, so 30 is 20% of 150.
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 15% of 200 = 200 × 15 ÷ 100 = 30.
How do I calculate percentage increase or decrease?
Use the formula (B − A) ÷ A × 100. A positive result is an increase, a negative result a decrease. From 80 to 100: (100 − 80) ÷ 80 × 100 = 25% increase.
How do I convert a fraction to a percentage?
Divide the numerator by the denominator and multiply by 100. For example, 3/4 = 0.75 × 100 = 75%.
How do I add or remove a percentage from a number?
To add 20% to 50, multiply by 1.20 to get 60. To remove 20%, multiply by 0.80 to get 40.
What is the difference between percentage and percentage points?
A percentage is a ratio out of 100. A percentage point is the arithmetic difference between two percentages — for example, 10% to 15% is a rise of 5 percentage points but a 50% relative increase.
Is the percentage calculator free?
Yes — completely free, works in your browser without sign-up, and no data ever leaves your device.
How much is 25% of 80?
25% of 80 = 80 × 25 ÷ 100 = 20. This is the same as multiplying 80 by 0.25.
What is 10% of 50?
10% of 50 = 50 × 10 ÷ 100 = 5. This is the same as multiplying 50 by 0.10.
Percentage Calculator — Solve Percent Problems in Seconds
Percentages appear everywhere: shopping discounts, tax rates, tips, grades and investment returns. Our free percentage calculator handles the three most common percent problems in one place. Type in your numbers, pick a mode, and get an instant answer — no downloads, no sign-up, just accurate math in your browser.
Three modes for every percent problem
- X is what percent of Y — express one number as a percentage of another.
- What is X% of Y — calculate the percentage value of any number.
- Percentage change from A to B — measure increases and decreases.
- Instant results with clear, rounded output and no page reloads.
- Works offline and privately — no data ever leaves your device.
- Fully localized in 11 languages.
Popular ways to use the percentage calculator
- Shopping discounts — check the real saving after a percent off.
- Tax and tip calculations at restaurants and checkout.
- Investment returns — measure percentage gains or losses.
- Grades and scores — convert marks into percentages.
- Business metrics — growth, margins and year-over-year change.
- Quick sanity checks on percentages you hear in news and ads.
Whether you are calculating a 20% tip, the percentage of a test you got right, or whether a price rise is as big as it looks, this calculator gives you a clear answer in seconds. Bookmark it for everyday math — from shopping carts to spreadsheets.