Percentage Calculator
What is 15% of 200? What percent is 30 of 200? How much did a price change? Pick a mode, type your numbers — the answer appears instantly, with the formula that produced it.
A is what percent of B?
Grades, shares, progress and test scores.
Result
15%
30 ÷ 200 × 100 = 15%
How it works
Choose a mode
Tap the chip that matches your question — percent of a number, a value as a percent, or change over time.
Type your numbers
The result recalculates on every keystroke, right from your phone's number keyboard.
Copy and use it
One tap puts the answer in your clipboard — paste it into a chat, invoice or homework.
Built for quick math
Instant answers
No submit button needed — every keystroke updates the result and its formula.
Everyday use
Shop discounts, tips, grade percentages, VAT, markups and growth rates in one place.
Nothing stored
Your numbers are never saved or shared. Open the page and calculate — that's it.
FAQ
How is the answer rounded?+
Choose between 0 and 6 decimal places. Thousands separators and decimal points follow standard number formatting.
What does Undefined mean?+
It means a division by zero — for example, asking what percent B is when B equals 0. Type a non-zero value and the answer returns.
Can I use it for discounts and markups?+
Yes. “A% of B” gives the discount amount, and “% change A → B” shows the markup or drop between an old and a new price.
How large can my numbers be?+
Enter any value from 0 to 1,000,000,000. If a result becomes extremely large, it is shown in scientific notation so it never breaks the layout.