How do you calculate percentages?

Divide the part by the whole and multiply by 100. For example, 50 out of 200 = (50 ÷ 200) × 100 = 25%.

How do you find percentage increase?

Subtract the original value from the new value, divide the result by the original value, and multiply by 100. Formula: ((New − Old) ÷ Old) × 100.

What is percentage decrease?

Percentage decrease measures how much a value has dropped relative to the original. Formula: ((Old − New) ÷ Old) × 100.

How do I calculate a discount?

Multiply the original price by the discount percentage divided by 100. For example, 20% off $80 = $80 × 0.20 = $16 discount, so you pay $64.

20% of 100 = (20 ÷ 100) × 100 = 20.

Percentage calculator that draws the whole

Pick the question you actually have. The answer resolves inside an explicit 100% field, with the formula and a check you can run backwards.

What are you trying to find?

What is X% of Y?

Percent%ofOf this number

0100% whole 80

20 is the part you solved for, 80 is the 100% whole, and the marked boundary sits at 25%.

25% means 25 out of every 100. Applied to 80, that gives 20.

Formula

Convert to decimal: 25% = 25 ÷ 100 = 0.25

Multiply: 0.25 × 80 = 20

Verify

0.25 × 100 = 25%

Check it backwards: the part divided by the whole returns the percent you entered.

Instant answer

What is 15% of 240?

15% of 240 is 36.

15% of 240 = 36. To find any percentage of a number, divide the percentage by 100 and multiply by the number.

Formula: Result = (Percentage ÷ 100) × Number
Definition: A percentage of a number is that number scaled by a fraction of one hundred: “per cent” literally means “per hundred”, so 15% means 15 hundredths.

Convert to decimal:15% = 15 ÷ 100 = 0.15
Multiply:0.15 × 240 = 36

Solve

Eight questions, one engine and one field. Each page opens the workbench on that question.

Learn

Guides that stand on their own — reasoning first, calculator optional.

Reference

Formulas, worked examples and edge cases to look up in a hurry.

Or type the question

Plain English works too — “what is 15% of 240”, “80 to 100 percent change”.

Percentage points are not percent

This single distinction causes more wrong percentage statements than any other. If a rate moves from 40% to 50%, it rose by 10 percentage points — but that is a 25% relative increase, because the change is measured against the starting rate of 40%.

0100% of the population

+10 percentage pointsthe drawn gap between the two rates+25% relativethe same gap measured against the first rate

Read the full explanation in percent vs percentage points.

Percentage Formula

The basic percentage formula is:

Percentage = (Part ÷ Whole) × 100

This formula converts a ratio into a percentage. For example, if you scored 45 out of 60 on a test: (45 ÷ 60) × 100 = 75%.

How to Calculate Percentage

Follow these three simple steps:

Divide the part by the whole (e.g. 30 ÷ 120 = 0.25)
Multiply by 100 (e.g. 0.25 × 100 = 25)
Add the % sign — the answer is 25%

Use the percentage calculator above to do this instantly for any values.

Common Percentage Calculations

Percentage Increase Formula

((New Value − Old Value) ÷ Old Value) × 100

Use the Percentage Increase Calculator for instant results.

Percentage Decrease Formula

((Old Value − New Value) ÷ Old Value) × 100

Use the Percentage Decrease Calculator for instant results.

Percentage Difference

Percentage difference compares two values by dividing their absolute difference by their average. Try the Percentage Difference Calculator.