How do I calculate what percentage one number is of another?

Divide the part by the whole, then multiply by 100. For example, 30 is what percentage of 120? 30 ÷ 120 × 100 = 25%. Use the 'What % is X of Y?' calculator above for instant results.

How do I calculate a percentage increase?

Subtract the original value from the new value, divide by the original value, then multiply by 100. Formula: ((New - Old) ÷ Old) × 100. Use the Percentage Change calculator above.

What is X percent of Y?

Multiply Y by X, then divide by 100. For example, 15% of 200 = 200 × 15 ÷ 100 = 30. Use the 'X% of Y' calculator above for any values.

Percentage Calculator

Six calculators covering every common percentage problem — instant results, nothing sent to any server.

Calculator 1

What is X% of Y?

What is % of ?

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Calculator 2

X is what % of Y?

is what % of ?

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Calculator 3

Percentage increase / decrease

From to

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Calculator 4

Find the original value

is % of what?

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Calculator 5

Add a percentage to a number

+ %

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Calculator 6

Subtract a percentage from a number

− %

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Percentage formulas

What is X% of Y?

Result = (X ÷ 100) × Y

Example: What is 15% of 200? → (15 ÷ 100) × 200 = 30

X is what percentage of Y?

Percentage = (X ÷ Y) × 100

Example: 30 is what % of 120? → (30 ÷ 120) × 100 = 25%

Percentage increase or decrease

Change % = ((New − Old) ÷ Old) × 100

Example: From 80 to 100 → ((100 − 80) ÷ 80) × 100 = +25%

If the result is negative, it's a decrease. If positive, it's an increase.

Find the original value

Original = Value ÷ (Percentage ÷ 100)

Example: 30 is 25% of what? → 30 ÷ (25 ÷ 100) = 30 ÷ 0.25 = 120

Common percentage reference

Quick lookup for the most frequently searched percentage values.

Percentage	Of 100	Of 200	Of 1,000
5%	5	10	50
10%	10	20	100
15%	15	30	150
20%	20	40	200
25%	25	50	250
33.3%	33.3	66.7	333.3
50%	50	100	500
75%	75	150	750

Tip: To quickly estimate 10% of any number, move the decimal point one place to the left. 10% of 3,450 = 345. Then double it for 20%, halve it for 5%, etc.

Everyday percentage examples

Tipping at a restaurant

A 15% tip on a $60 bill: (15 ÷ 100) × 60 = $9. A 20% tip: (20 ÷ 100) × 60 = $12. Use Calculator 1 above — enter the tip % and the bill amount.

Sale discounts

A jacket costs $120 and is 30% off. Use Calculator 6: 120 − 30% = $84. You save $36.

Pay rises

Your salary goes from $65,000 to $71,500. Use Calculator 3: from 65000 to 71500 = +10% increase.

Test scores

You got 42 out of 60 questions right. Use Calculator 2: 42 is what % of 60? = 70%.

VAT / GST / sales tax

Price before GST is $450, GST is 15% (New Zealand rate). Use Calculator 5: 450 + 15% = $517.50 including GST. To find the GST amount alone: (15 ÷ 100) × 450 = $67.50.

Frequently asked questions

How do I calculate a percentage on a calculator?

For X% of Y: type Y × X ÷ 100. For example, 15% of 200: press 200 × 15 ÷ 100 = 30. On calculators with a % button: type 200 × 15% and the calculator applies the division by 100 automatically.

What is the difference between percentage and percentage points?

A percentage point is an absolute difference between two percentages. If interest rates go from 2% to 3%, that's an increase of 1 percentage point — but a 50% increase in the rate itself. "Percentage change" and "percentage points" measure different things. Use "percentage points" when comparing two percentages directly.

How do I calculate the original price before a discount?

Use Calculator 4 (Find the original value). If an item now costs $85 after a 15% discount, the sale price is 85% of the original. So: 85 is 85% of what? → 85 ÷ 0.85 = $100 original price. Alternatively, divide the sale price by (1 − discount/100).

How do I calculate percentage change between two numbers?

Use Calculator 3 above. The formula is: ((New Value − Old Value) ÷ Old Value) × 100. A positive result is an increase; a negative result is a decrease. Always divide by the original (old) value, not the new one.

Does this calculator store my numbers?

No. All calculations happen entirely in your browser using JavaScript. Nothing is sent to any server. Your numbers are never stored or logged anywhere.

Percentage Calculator

Percentage formulas

What is X% of Y?

X is what percentage of Y?

Percentage increase or decrease

Find the original value

Common percentage reference

Everyday percentage examples

Tipping at a restaurant

Sale discounts

Pay rises

Test scores

VAT / GST / sales tax

Frequently asked questions

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