How do I calculate 20% of a number?

Multiply the number by 0.20, or use the 'What is X% of Y?' tab and enter 20 and your number.

What is the formula for percentage change?

Percentage change = ((New Value - Old Value) / |Old Value|) × 100. A positive result means an increase; negative means a decrease.

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

Divide the part by the total and multiply by 100. For example, 30 out of 120 is (30 / 120) × 100 = 25%.

How do I add a percentage to a number?

Multiply the original number by (1 + percentage/100). For example, to add 15% to 200, calculate 200 × 1.15 = 230.

How to convert a fraction to a percentage?

Divide the numerator by the denominator and multiply the result by 100. For example, 3/4 becomes (3 / 4) × 100 = 75%.

What's the difference between percentage and percentage points?

Percentage points measure the arithmetic difference between two percentages. Going from 10% to 15% is a 5 percentage point increase, but a 50% relative increase.

Can I calculate a percentage greater than 100%?

Yes. A value can be more than 100% of another — for example, 250 is 125% of 200.

Math

↵ to calculate

Percentage Calculator — Find % of Any Number Instantly

Calculate percentages easily! Find what percent of a number is, see how much something changed, or figure out what percentage one number is of another.

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How to use this calculator

👉 Fill in the boxes below and your answer appears instantly — no maths needed, we do it all for you! 🎉

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In plain English — what does this do?

🍬 Say you have 100 candies. If you eat 20 of them, you ate 20% (20 out of 100). This tool helps you quickly find out ‘what part of a number is something?’ — super easy!

📌 Direct Answer & Summary

A percentage calculator helps you find what percent one number is of another, calculate a percentage of a value, or determine percentage change between two numbers. Percentages express a ratio out of 100 and are used everywhere from discounts and taxes to test scores and statistics.

🔢 Percentage (%)

Type a number like 15 (meaning 15 out of 100)

🎯 of this Value

The total number you want % of

What is Percentage Calculator — Find % of Any Number Instantly?

How to use it

1️⃣ Select the mode that matches your question: 'What is X% of Y?', '% Change', or 'X is what % of Y?'.
2️⃣ Enter the known values into the input fields.
3️⃣ The result updates instantly as you type.
4️⃣ Switch between modes to answer different types of percentage questions without clearing your inputs.

Formula & Variables

1. Percentage of a value: P = (X ÷ 100) × Y 2. Percentage change: Δ% = [(V₂ − V₁) ÷ |V₁|] × 100 3. What percent is X of Y: Rate% = (X ÷ Y) × 100

Variable Definitions:

P Portion or resulting value representing the designated percentage

X Percentage rate (parts per hundred)

Y Base number or reference whole

Δ% Relative percentage increase (positive) or decrease (negative)

V₁, V₂ Initial starting value (V₁) and final ending value (V₂)

💡 See it in action — a real example

To find 15% of 200: (15 ÷ 100) × 200 = 30. To find the percentage change from 80 to 100: [(100 − 80) ÷ 80] × 100 = (20 ÷ 80) × 100 = +25% increase.

📊 Common Percentage, Decimal & Fraction Conversion Chart

Standard mathematical equivalencies frequently used in retail discounts, finance, and statistics.

Percentage	Decimal Equivalent	Simplified Fraction	Mental Math Shortcut
5%	0.05	1 / 20	Divide by 10, then divide by 2
10%	0.10	1 / 10	Move decimal point one place to the left
12.5%	0.125	1 / 8	Divide by 8 (or halve three times)
15%	0.15	3 / 20	Find 10%, plus half of that (10% + 5%)
20%	0.20	1 / 5	Divide by 5 (or double 10%)
25%	0.25	1 / 4	Divide by 4 (or halve twice)
33.33%	0.3333...	1 / 3	Divide by 3
50%	0.50	1 / 2	Divide by 2
66.67%	0.6667...	2 / 3	Divide by 3, then multiply by 2
75%	0.75	3 / 4	Divide by 4, then multiply by 3

* To convert any percentage to decimal, move the decimal point two places to the left.

📊 Percentage Formulas in Common Everyday Phrasing

Translating natural language questions into direct arithmetic calculations.

Everyday Question	Example Scenario	Direct Mathematical Formula	Result
What is P% of X?	What is 15% tip on $60?	Result = (15 ÷ 100) × 60	$9.00 tip
X is what % of Y?	Score 45 out of 50 on test	Result = (45 ÷ 50) × 100	90% grade
What is % change from X to Y?	Gas price went from $3.00 to $3.75	Result = [(3.75 − 3.00) ÷ 3.00] × 100	+25% increase
X is P% of what number?	$120 is 20% of total budget	Result = 120 ÷ (20 ÷ 100)	$600 total budget
Add P% to X (Markup)	Add 8% sales tax to $50 item	Result = 50 × (1 + 0.08)	$54.00 total

❓ Common questions

How do I calculate 20% of a number?: Multiply the number by 0.20, or use the 'What is X% of Y?' tab and enter 20 and your number.
What is the formula for percentage change?: Percentage change = ((New Value - Old Value) / |Old Value|) × 100. A positive result means an increase; negative means a decrease.
How do I find what percentage one number is of another?: Divide the part by the total and multiply by 100. For example, 30 out of 120 is (30 / 120) × 100 = 25%.
How do I add a percentage to a number?: Multiply the original number by (1 + percentage/100). For example, to add 15% to 200, calculate 200 × 1.15 = 230.
How to convert a fraction to a percentage?: Divide the numerator by the denominator and multiply the result by 100. For example, 3/4 becomes (3 / 4) × 100 = 75%.
What's the difference between percentage and percentage points?: Percentage points measure the arithmetic difference between two percentages. Going from 10% to 15% is a 5 percentage point increase, but a 50% relative increase.
Can I calculate a percentage greater than 100%?: Yes. A value can be more than 100% of another — for example, 250 is 125% of 200.