Math · Percentage

Percentage Calculator

Calculate percentages, percentage changes, discounts, markups, and ratios quickly and accurately.

Calculate Percentage

Live Math

Percentage (%)

Total Number (Y)

Quick Test Examples:

Calculation Result

Exact Output

Answer

100

20% of 500 is equal to 100

Mathematical Formula: (20 ÷ 100) × 500

Step-by-Step Computation: 0.2 × 500

Business & Shopping

Discount, Markup & Reverse Tools

Practical calculators tailored for retail shopping, merchant pricing, and profit margin analysis.

Discount Calculator

Markup Calculator

Reverse Discount

Percentage Formulas Explained

A percentage represents a fraction of 100 (from Latin per centum, meaning "by the hundred"). Below are the foundational mathematical formulas for standard percentage operations:

1. Percentage of a Number (What is X% of Y?)

Percentage = (X ÷ 100) × Y

Divide the percentage by 100 to obtain its decimal multiplier, then multiply by the total number.

2. Finding What Percentage X Is of Y

Percentage = (X ÷ Y) × 100

Divide the part (X) by the total (Y) and multiply by 100 to express the ratio as a percentage.

3. Percentage Increase

Increase % = ((New − Original) ÷ Original) × 100

Subtract the original value from the new value, divide by the original value, and multiply by 100.

4. Percentage Decrease

Decrease % = ((Original − New) ÷ Original) × 100

Subtract the new value from the original, divide by the original, and multiply by 100.

5. Percentage Difference

Difference % = |A − B| ÷ ((A + B) ÷ 2) × 100

Used when comparing two non-sequential values where neither is considered the initial baseline. Divide the absolute difference by the average of both values.

6. Retail Discount & Markup Formulas

Discount Amount = Original Price × (Discount% ÷ 100)
Final Price = Original Price − Discount Amount

Selling Price = Cost Price + (Cost Price × Markup% ÷ 100)

Original Price = Final Price ÷ (1 − (Discount% ÷ 100))

Worked Practical Examples

Step-by-step solutions to common real-world percentage calculations:

What is 15% of 2,000?
• Step 1: 15 ÷ 100 = 0.15
• Step 2: 0.15 × 2,000 = 300

80 is what percentage of 400?
• Step 1: 80 ÷ 400 = 0.20
• Step 2: 0.20 × 100 = 20%

Price increases from ₹1,000 to ₹1,200
• Step 1: Change = ₹1,200 − ₹1,000 = ₹200
• Step 2: ₹200 ÷ ₹1,000 = 0.20
• Step 3: 0.20 × 100 = 20% increase

₹2,000 item with a 25% discount
• Discount: ₹2,000 × 0.25 = ₹500
• Final Price: ₹2,000 − ₹500 = ₹1,500

Cost ₹1,000 with a 30% markup
• Markup Profit: ₹1,000 × 0.30 = ₹300
• Selling Price: ₹1,000 + ₹300 = ₹1,300

Where Are Percentages Used in Everyday Life?

Percentages are among the most versatile mathematical tools used across personal finance, commerce, education, and health:

🛍️ Shopping & Discounts

Calculating retail sales, seasonal discounts ("30% off"), promotional coupons, and cash-back rewards on purchases.

🎓 Academic Scores & Exams

Converting total test marks into percentages or percentiles for university admissions and academic evaluations.

💼 Salary Appraisals & Raises

Evaluating annual compensation adjustments, bonus payouts, commission rates, and cost-of-living increases.

📈 Business Margins & Markup

Establishing profitable pricing for wholesale goods, calculating gross margins, and evaluating inventory turnover.

🏛️ Taxes & Statutory Duties

Computing GST slabs, customs tariffs, income tax deductions, and municipal property taxes.

📊 Statistics & Metrics

Tracking demographic changes, market share comparisons, election polling ratios, and performance metrics.

Help & Answers

Frequently Asked Questions

Clear answers to common questions regarding percentage mathematics, discounts, and everyday calculations.

How do I calculate a percentage of a number?

To find X% of Y, convert the percentage into a decimal by dividing it by 100, then multiply by the number: (X ÷ 100) × Y. For example, 20% of 500 is (20 ÷ 100) × 500 = 100.

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

Divide the part by the whole number and multiply the result by 100: (Part ÷ Whole) × 100. For example, if you scored 80 marks out of 400: (80 ÷ 400) × 100 = 20%.

How do I calculate percentage increase?

Subtract the original value from the new value, divide by the original value, and multiply by 100: ((New − Original) ÷ Original) × 100. If an item rises from ₹500 to ₹600: ((600 − 500) ÷ 500) × 100 = 20% increase.

How do I calculate percentage decrease?

Subtract the new value from the original, divide by the original, and multiply by 100: ((Original − New) ÷ Original) × 100. If a price drops from ₹500 to ₹400: ((500 − 400) ÷ 500) × 100 = 20% decrease.

What is percentage difference and when is it used?

Percentage difference compares two numbers when neither is an initial or baseline value. It divides the absolute difference by the average of the two numbers: |A − B| ÷ ((A + B) ÷ 2) × 100.

How do I calculate a discount during a sale?

Multiply the original price by the discount percentage divided by 100 to get the discount amount. Then subtract that discount from the original price to find the final price. For a ₹2,000 item at 20% off: Discount = ₹400, Final Price = ₹1,600.

How do I calculate the original price after a discount?

Divide the final discounted price by (1 − Discount% ÷ 100): Original Price = Final Price ÷ (1 − (Discount% ÷ 100)). For instance, if you paid ₹800 after a 20% discount: ₹800 ÷ 0.80 = ₹1,000 original price.

What is markup percentage and how is it different from profit margin?

Markup is the percentage added to the cost price to determine the retail selling price. Profit margin, by contrast, is the profit expressed as a percentage of the final selling price. A 25% markup on a ₹1,000 cost yields a ₹1,250 selling price (20% margin).

Can percentages be greater than 100%?

Yes. A percentage greater than 100% simply means the quantity exceeds the original baseline. For example, if your investment grows from ₹1,000 to ₹3,000, that represents a 200% increase (or 300% of the original value).

Is this percentage calculator free and private?

Yes, 100% free and completely private. All calculations run locally in your web browser. No figures or personal data are stored, tracked, or sent to external servers.

Disclaimer: This percentage calculator is provided for educational and general informational purposes only. While calculations follow standard mathematical and commercial formulas, commercial terms, trade discounts, and tax considerations may vary based on statutory regulations.