What is X% of Y?
What is % of
X is what percent of Y?
is what % of
Percentage increase / decrease
From to
Work out percentages three ways — percent of a number, X as a percent of Y, and percentage increase or decrease.
Percentage questions show up in different shapes — working out a 20% tip, checking what fraction of a budget you've spent, or measuring how much a price rose since last year. Rather than remembering three different formulas, pick the calculator that matches your question and get the answer worked out instantly in your browser.
Use "What is X% of Y?" for discounts or tips, "X is what percent of Y?" to find a ratio, or "Percentage increase/decrease" to measure change between two values.
Type the two values into the fields of whichever card matches your question.
Click the "=" button on that card and the answer appears directly underneath.
Runs in your browser — nothing uploaded
Covers common percent questions
Results in one click
No registration required
Use the first calculator: enter the percentage and the number, for example 20% of 150, and click Calculate to get the result instantly. Completely free.
Use the second calculator: enter both numbers, for example 30 is what percent of 120, and it returns the percentage.
Use the third calculator: enter the original and new values, and it shows the percentage change, positive for an increase and negative for a decrease.
No. All calculations happen entirely in your browser. Nothing is uploaded — guaranteed privacy.
Yes. You can enter decimal numbers and percentages, and results are rounded to a sensible number of decimal places.
Percent of a number is (percent ÷ 100) × number. X as a percent of Y is (X ÷ Y) × 100. Percentage change is ((new − old) ÷ old) × 100.