Percentage Calculator
Find X% of a number, what percent one number is of another, and the percentage change between two values, live as you type.
What is X% of Y?
X is what percent of Y?
Percentage change from X to Y
Everything is calculated in your browser. The numbers you type are never uploaded.
How to calculate percentages online
Find X% of a number
Type the percentage and the number into the first row. The answer appears as you type, so 15 and 60 shows 9 straight away.
Find what percent X is of Y
Use the second row to express one number as a percentage of another, for example 45 is 75% of 60.
Measure percentage change
Enter a starting value and an ending value in the third row. The result carries a plus or minus sign and states whether it is an increase or a decrease.
Why use this tool
Three calculators in one
Percent of a number, X as a percent of Y, and percentage change all sit on one page, so you never hunt for the right variant.
Live results as you type
Every row recalculates the moment a number changes. There is no button to press and nothing to submit.
Signed percentage change
The change result shows a plus or minus sign and states increase or decrease, so the direction is never ambiguous.
Copy any result
Each row has its own copy button that puts a plain-text summary of that calculation on your clipboard.
Decimals and negatives accepted
Inputs take decimal and negative numbers, and results are rounded to two decimal places with thousands separators.
Nothing leaves your browser
All the maths runs on the page itself. The numbers you type are never uploaded, stored, or logged.
About this tool
Most percentage questions come down to one of three forms, and this calculator answers all of them on one page. The first row finds a percentage of a number: a 15 percent tip on a 60 dollar bill is 15% of 60, which is 9. The second row works in reverse and tells you what percent one number is of another: 45 out of 60 is 75%. The third row measures the percentage change between a starting value and an ending value, the form behind price rises, pay changes, and growth figures.
Direction matters with percentage change, so the result always carries a sign and a word. A price that moves from 80 to 92 shows as a +15% increase, while the reverse move from 92 to 80 is a -13.04% decrease, not 15. The two differ because the change is always measured against the starting value, and mixing them up is one of the most common percentage mistakes. Results are rounded to two decimal places with trailing zeros trimmed, and every field accepts decimals and negative numbers.
Each row recalculates as you type and has its own copy button, so moving an answer into a message or a spreadsheet is one click. The numbers never leave your browser; nothing is uploaded or stored. For the specific jobs behind these forms, the tip calculator splits a bill, the discount calculator works out sale prices, and the compound interest calculator handles percentage growth over time.
Frequently asked questions
- How do I calculate X percent of Y?
- Multiply the number by the percentage and divide by 100. The first row does this for you: type 15 and 60 and it shows 9, which is a 15 percent tip on a 60 dollar bill.
- How do I work out what percent one number is of another?
- Divide the first number by the second and multiply by 100. The second row handles it live: 45 of 60 shows 75%. If the second number is zero the tool explains that it cannot divide by zero instead of showing a result.
- How is percentage change calculated?
- The difference between the ending and starting values is divided by the size of the starting value and multiplied by 100. Going from 80 to 92 is a +15% increase; going from 92 back to 80 is a -13.04% decrease, because the change is measured against where you started.
- What is the difference between percentage change and percentage points?
- Percentage change is relative to the starting value; percentage points are the plain difference between two percentages. A rate moving from 40% to 50% rises by 10 percentage points but is a 25% increase.
- How are results rounded, and can I enter negative numbers?
- Results show up to two decimal places with trailing zeros trimmed and thousands separators on large numbers. Every field accepts decimals and negative numbers, and the change result keeps its sign so the direction stays clear.
- Are the numbers I enter private?
- Yes. Every calculation runs in your browser. The numbers you type are never uploaded, stored, or logged.
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