Home/Calculators/Percentage Calculator

Percentage Calculator

Calculate percentages instantly with 3 quick solutions. Perfect for students, business calculations, and everyday math with step-by-step explanations.

Percentage Calculator

What is ? % of ?

What is%
of?

Quick Examples:

• What is 25% of 200? = 50

• 50 is what % of 200? = 25%

• 50 is 25% of what? = 200

Select a calculation type and enter values

Choose from the Quick Solutions dropdown and click Calculate

Need Help with Percentages?

Our expert tutors can help you master percentage calculations, understand formulas, and excel in mathematics. Get personalized one-on-one guidance tailored to your learning style.

Understanding Percentages

A percentage is a way of expressing a number as a fraction of 100. The word "percent" comes from the Latin "per centum," which means "by the hundred." Percentages are one of the most common ways to express proportions and are used extensively in everyday life, from calculating discounts and taxes to understanding statistics and financial data.

Our comprehensive percentage calculator provides three essential calculation types that cover all common percentage scenarios. Whether you're a student learning mathematics, a business professional analyzing data, or someone making everyday calculations like calculating tips or discounts, this tool provides instant, accurate results with detailed step-by-step explanations.

The calculator supports all three fundamental percentage calculations: finding what a percentage of a number is, determining what percentage one number is of another, and calculating the whole when you know a part and its percentage. Each calculation includes a clear formula and breakdown of the mathematical steps involved.

How to Use This Percentage Calculator

Our calculator is designed for maximum ease of use. Simply select your calculation type from the Quick Solutions dropdown and enter your values:

1

Choose Calculation Type

Select from the "Quick Solutions" dropdown: "What is X% of Y?", "X is what % of Y?", or "X is Y% of what?"

2

Enter Your Values

Fill in the input fields with your numbers. The calculator will guide you with placeholders showing example values.

3

Click Calculate

Press the Calculate button to instantly see your answer along with the formula and detailed step-by-step solution.

4

Review the Solution

Study the step-by-step breakdown to understand how the percentage was calculated. Use the Clear button to start a new calculation.

The Three Essential Percentage Calculations

1. What is X% of Y?

This is the most common type of percentage calculation. Use this when you want to find a percentage of a number.

Formula:

(Percentage ÷ 100) × Number = Answer

Example:

What is 25% of 200?

(25 ÷ 100) × 200 = 0.25 × 200 = 50

Common Uses: Calculating discounts, tips, taxes, commission, interest rates, and marks in exams.

2. X is what % of Y?

This calculation finds what percentage one number represents of another number. Perfect for calculating ratios, portions, and comparisons.

Formula:

(Number ÷ Total) × 100 = Percentage

Example:

50 is what % of 200?

(50 ÷ 200) × 100 = 0.25 × 100 = 25%

Common Uses: Finding test scores, completion percentages, market share, conversion rates, and efficiency ratings.

3. X is Y% of what?

This reverse calculation finds the whole when you know a part and its percentage. Useful for working backwards from partial information.

Formula:

Number ÷ (Percentage ÷ 100) = Whole

Example:

50 is 25% of what?

50 ÷ (25 ÷ 100) = 50 ÷ 0.25 = 200

Common Uses: Finding original prices before discounts, total budgets from partial spending, and full populations from sample data.

Real-World Applications of Percentages

Percentages are everywhere in daily life. Understanding how to calculate them is an essential life skill:

🛍️ Shopping & Discounts

Calculate sale prices, compare deals, and understand how much you're saving. A 30% discount on a $100 item means you pay $70.

Example: What is 30% off $100?

30% of $100 = $30 discount

Final price = $100 - $30 = $70

💰 Finance & Banking

Understand interest rates, loan payments, investment returns, and compound growth. A 5% annual interest on $1000 earns $50 per year.

Example: 5% interest on $1000

5% of $1000 = $50

Balance after 1 year = $1050

📊 Business & Analytics

Track growth rates, profit margins, market share, and performance metrics. If sales grew from 100 to 150 units, that's a 50% increase.

Example: Sales growth

From 100 to 150 units

(150-100)/100 × 100 = 50% growth

📚 Education & Grades

Calculate test scores, grade percentages, and academic performance. Scoring 45 out of 50 questions correct is 90%.

Example: Test score

45 correct out of 50 questions

(45/50) × 100 = 90%

🍽️ Tips & Service Charges

Calculate appropriate tips at restaurants and for services. A 15% tip on a $50 meal is $7.50.

Example: Restaurant tip

15% tip on $50 bill

15% of $50 = $7.50

📈 Statistics & Data

Understand survey results, polls, and demographic data. If 250 out of 1000 people prefer option A, that's 25%.

Example: Survey results

250 out of 1000 respondents

(250/1000) × 100 = 25%

Common Mistakes to Avoid

When working with percentages, watch out for these frequent errors:

❌ Forgetting to Divide by 100

Many people forget that percent means "per hundred." You must divide the percentage by 100 before multiplying.

Wrong: 25% of 200 = 25 × 200 = 5000 ✗

Correct: 25% of 200 = (25 ÷ 100) × 200 = 50 ✓

❌ Confusing "Of" and "From"

"X is Y% of Z" and "X is Y% from Z" are different. "Of" means multiply, "from" means the difference.

50 is 25% of 200 (50 = 25% × 200) ✓

50 is 75% from 200 (200 - 50 = 150 = 75% of 200) ✓

❌ Reversing the Numbers

Pay attention to which number is the part and which is the whole. Order matters in percentage calculations.

Wrong: 50 is what % of 25? = 50% ✗

Correct: 50 is what % of 25? = 200% ✓

(50 can be more than 100% of a smaller number!)

❌ Adding/Subtracting Percentages Incorrectly

You can't simply add or subtract percentages without considering their base values.

Price increases 50% then decreases 50%:

Wrong: Final price = Original (50% - 50% = 0% change) ✗

Correct: $100 + 50% = $150, then $150 - 50% = $75 ✓

❌ Dividing by Zero

You cannot calculate "X is what % of 0?" because division by zero is undefined.

50 is what % of 0? = Undefined ✗

The denominator (total) cannot be zero

Percentage Tips and Shortcuts

Master these mental math tricks to calculate percentages quickly:

💡 10% Shortcut

To find 10%, just move the decimal point one place to the left. Then multiply or divide for other percentages.

10% of 250 = 25 (move decimal left)

20% of 250 = 25 × 2 = 50

5% of 250 = 25 ÷ 2 = 12.5

💡 1% Shortcut

To find 1%, move the decimal point two places to the left. Perfect for calculating tips and small percentages.

1% of 500 = 5 (move decimal left twice)

3% of 500 = 5 × 3 = 15

15% tip on $50 = ($0.50 × 15) = $7.50

💡 50% and 25% Shortcuts

50% is half, 25% is one quarter. Use division instead of percentage formula.

50% of 80 = 80 ÷ 2 = 40

25% of 80 = 80 ÷ 4 = 20

75% of 80 = (80 ÷ 4) × 3 = 60

💡 Reversibility Trick

X% of Y = Y% of X. This symmetry can make mental calculations easier.

12% of 50 = 50% of 12 = 6

4% of 75 = 75% of 4 = 3

16% of 25 = 25% of 16 = 4

💡 Building Up Method

Break complex percentages into simpler ones that are easier to calculate.

35% of 200:

= (10% × 3) + 5%

= (20 × 3) + 10 = 60 + 10 = 70

Frequently Asked Questions

What is a percentage?

A percentage is a number or ratio expressed as a fraction of 100. It is denoted using the percent sign "%". For example, 45% (read as "forty-five percent") is equal to 45/100, or 0.45. Percentages are used to express how large or small one quantity is relative to another quantity.

How do you calculate a percentage of a number?

To calculate a percentage of a number, convert the percentage to a decimal by dividing by 100, then multiply by the number. For example, to find 20% of 150: (20 ÷ 100) × 150 = 0.20 × 150 = 30. Alternatively, you can use the formula: (Percentage/100) × Number = Result.

How do you convert a decimal to a percentage?

To convert a decimal to a percentage, multiply the decimal by 100 and add the percent sign. For example, 0.75 as a percentage is 0.75 × 100 = 75%. Similarly, 0.5 = 50%, 1.2 = 120%, and 0.03 = 3%. You can think of it as moving the decimal point two places to the right.

How do you convert a fraction to a percentage?

To convert a fraction to a percentage, divide the numerator by the denominator, then multiply by 100. For example, 3/4 as a percentage: (3 ÷ 4) × 100 = 0.75 × 100 = 75%. Similarly, 1/2 = 50%, 1/4 = 25%, and 3/5 = 60%.

Can a percentage be greater than 100%?

Yes! Percentages can be greater than 100%. This occurs when a value is larger than the reference value. For example, if sales increased from 50 to 150 units, the growth is 200% (150 is 200% more than the original 50, or 300% of the original value). Percentages over 100% are common in growth rates, returns on investment, and comparisons.

What's the difference between percentage and percentile?

A percentage is a fraction of 100 (like scoring 80% on a test means 80 out of 100). A percentile is a value below which a certain percentage of observations fall (scoring in the 80th percentile means you scored better than 80% of people). They're related but different concepts used in different contexts.

How do you calculate percentage increase or decrease?

To calculate percentage change: ((New Value - Old Value) / Old Value) × 100. If positive, it's an increase; if negative, it's a decrease. For example, if a price goes from $100 to $120: ((120 - 100) / 100) × 100 = 20% increase. If it goes from $100 to $80: ((80 - 100) / 100) × 100 = -20% decrease.

How do you add or subtract percentages?

You cannot simply add or subtract percentages unless they're of the same base value. Convert each percentage to its actual value first, then add or subtract those values. For example, if product A increased 10% and product B increased 20%, you can't say the total increase is 30% without knowing the original values of A and B.

What is the fastest way to calculate 15% for tips?

To quickly calculate a 15% tip: First find 10% by moving the decimal one place left, then find 5% by halving the 10% value, and add them together. For example, on a $60 bill: 10% = $6, 5% = $3, so 15% = $6 + $3 = $9. Or simply move the decimal left one place and add half that amount.

How accurate is this percentage calculator?

Our percentage calculator is 100% accurate for all standard calculations. It uses precise mathematical formulas and displays results with appropriate decimal places. The step-by-step solutions show exactly how each calculation is performed, ensuring transparency and educational value. You can trust this calculator for homework, business, and everyday percentage calculations.

Conclusion

Mastering percentage calculations is an essential life skill that applies to countless situations in education, business, finance, and daily life. Whether you're calculating discounts while shopping, determining test scores, analyzing business metrics, or planning your finances, understanding percentages empowers you to make informed decisions.

Our free percentage calculator simplifies all three fundamental types of percentage calculations with instant results and detailed step-by-step explanations. The Quick Solutions dropdown makes it easy to switch between calculation types, and the clear formula display helps you understand the mathematical reasoning behind each answer.

By using this calculator regularly and studying the step-by-step solutions, you'll develop a deeper intuition for percentages and improve your mental math skills. Remember the shortcuts and tips we've shared to calculate percentages quickly in your head, and always double-check your work to avoid common mistakes.

Start calculating percentages now with our free calculator!

Get instant, accurate results with detailed explanations for all your percentage needs.