Percentage Calculator

1. Pick the question that matches yours: “What is X% of Y?”, “X is what percent of Y?”, or “% change from X to Y”.
2. Type the two numbers. Leave out % and $ signs — the calculator only needs the figures.
3. Read the answer and the one-line formula under it, so you can repeat it by hand.

Quick answers

What is 20% of 2,400?

2,400 × 0.20 = 480. Choose “What is X% of Y?” with X = 20 and Y = 2,400.

What is 4% of $180?

180 × 0.04 = $7.20.

16.67 is what percent of 20?

16.67 ÷ 20 × 100 = 83.35%. The gap, 20 − 16.67 = 3.33, is 16.65% of 20.

What is the percent change from 80 to 100?

(100 − 80) ÷ 80 × 100 = 25% increase. Going back from 100 to 80 is a 20% decrease.

Edge cases and limits

• This page answers three fixed percentage questions. It does not evaluate typed expressions such as “2400 x 20%”; enter the two numbers instead.
• Percent change from 0 is undefined. Use the Percentage Difference Calculator to compare against zero.
• To add or remove a percentage in one step (for example “3,200 plus 20%”), use the Add or Subtract Percentage Calculator.

All three questions come from the same relationship between a part, a whole, and a rate. Naming which one you are solving for is most of the work.

• X% of Y = X ÷ 100 × Y
• X is what percent of Y = X ÷ Y × 100
• Percentage change from X to Y = (Y − X) ÷ |X| × 100
• Percentage change is positive for an increase and negative for a decrease
• A fraction is just the second question: 3/4 as a percent is 3 ÷ 4 × 100 = 75%
• To subtract a percentage, take Y − (X% of Y) — the first mode shows that line directly

Each mode answers a different question. "Percent of" scales a number, "is what percent of" turns two numbers into a share, and percentage change measures movement from a starting value — positive for an increase, negative for a decrease.

Common mistakes and assumptions

• Reversing the two numbers in a percentage change. The first value is the baseline you divide by.
• Expecting a drop and a rise of the same percentage to cancel out — they do not, because the base changes.
• Using percentage change when you want percentage points; a rate moving from 4% to 5% is a one-point rise and a 25% change.

A price moved from $180 to $216 and you want the percentage change.

1. 1Absolute change = $216 − $180 = $36.
2. 2Percentage change = $36 ÷ $180 × 100 = 20% — an increase.
3. 3Note that going back from $216 to $180 is a 16.67% decrease, not 20%: the base changed.
4. 4Switch to "X is what percent of Y" with 36 and 180 to confirm the same 20%.
5. 5Switch to "What is X% of Y" with 20 and 180 to get the $36 back.

How do I work out a percentage of a number, like 20% of 3,200?

Divide the percentage by 100 and multiply: 20 ÷ 100 × 3,200 = 640. The same steps give 4% of 180 = 0.04 × 180 = 7.2. Use the "What is X% of Y" mode, which also shows the number increased and decreased by that percentage.

What does "X percent more than Y" mean?

It means Y plus X% of Y. 25% more than 80 is 80 + 20 = 100. To find how much more one number is than another as a percent, use the change mode: from 80 to 100 is a 25% increase.

Why isn't a 20% increase reversed by a 20% decrease?

Because the base changes. Going up 20% from 100 gives 120; taking 20% off 120 gives 96. To undo a 20% increase you need a 16.67% decrease.

Can I use negative numbers?

Yes. Percentage change uses the absolute value of the starting number so the sign of the result still reads correctly as an increase or a decrease.

What is a percentage point?

A percentage point is a plain difference between two percentages. Going from 4% to 6% is a rise of 2 percentage points, but a 50% increase.

How do I find what percent one number is of another?

Divide the part by the whole and multiply by 100. The "X is what percent of Y" mode here does that division for you and shows the decimal alongside the percentage.

How do I take a percentage off a price?

Use the first mode and read the "Y decreased by X%" line, or use the discount calculator, which also shows what you save.

How do I turn a fraction into a percentage?

A fraction is a part over a whole, so use "X is what percent of Y" with the top number as X and the bottom as Y. For 3/4, enter 3 and 4 to get 75%.

What is the difference between percentage change and percentage difference?

Percentage change measures movement from a starting value, so the order matters. Percentage difference compares two values symmetrically against their average, with no starting point. Use the change mode here for the first, and the percentage difference calculator for the second.

Worked answers with real figures and stated assumptions, written around the question people usually arrive with.

• Percentage change vs percentage pointsThe difference between a 5-point move and a 25% move, with worked examples and the formulas behind both.