🔢 What is X% of Y? Live
📋 Result & Explanation
Choose a mode on the left, enter your values, and the result appears here in real time.
📊 Free Percentage Calculator — 12 Tools in 1
Calculate percentages instantly: X% of Y, "X is what % of Y", percentage increase/decrease, discounts, GST, tips, marks, and more. All calculations run 100% in your browser — no data is sent to any server.
What is a percentage calculator? A percentage calculator is a free online tool that instantly computes percentages — from "What is 15% of 250?" to "What is the percentage increase from 80 to 100?" and "What is the final price after a 30% discount?". Percentages are used everywhere: shopping, taxes, grades, GST, tips, interest rates, and business metrics. According to the U.S. Bureau of Labor Statistics, percentage calculations underpin inflation, wage growth, and economic indicators. As mathematician John Allen Paulos wrote: "Innumeracy — the inability to comfortably handle the mathematics of everyday life — is a real handicap." This 12-in-1 calculator makes percentages effortless. Zero signup, zero tracking.
Choose a Calculation Mode
Percentage Formula Cheat Sheet — All 12 Calculations
Every percentage calculation follows one of these core formulas. Master these and you'll never need to guess again.
| Calculation | Formula | Example |
|---|---|---|
| What is X% of Y? | (X ÷ 100) × Y |
15% of 250 = (15 ÷ 100) × 250 = 37.5 |
| X is what % of Y? | (X ÷ Y) × 100 |
30 is what % of 150? = (30 ÷ 150) × 100 = 20% |
| Percentage increase | ((New − Old) ÷ Old) × 100 |
80 → 100 = ((100 − 80) ÷ 80) × 100 = 25% |
| Percentage decrease | ((Old − New) ÷ Old) × 100 |
100 → 80 = ((100 − 80) ÷ 100) × 100 = 20% |
| Percentage difference | |A − B| ÷ ((A + B) ÷ 2) × 100 |
50 & 70 = |50 − 70| ÷ 60 × 100 = 33.33% |
| Discounted price | Price × (1 − Discount ÷ 100) |
₹1000 at 30% off = ₹1000 × 0.70 = ₹700 |
| GST-inclusive price | Price × (1 + GST ÷ 100) |
₹1000 + 18% GST = ₹1180 |
| Reverse percentage | Value ÷ (Percent ÷ 100) |
₹300 is 25% of = 300 ÷ 0.25 = ₹1200 |
| Add % to number | N × (1 + P ÷ 100) |
200 + 15% = 200 × 1.15 = 230 |
| Subtract % from number | N × (1 − P ÷ 100) |
200 − 15% = 200 × 0.85 = 170 |
| Marks percentage | (Marks ÷ Total) × 100 |
425 out of 500 = (425 ÷ 500) × 100 = 85% |
| Tip calculator | Bill × (Tip ÷ 100) |
₹2000 + 10% tip = ₹200 extra = ₹2200 total |
Frequently Asked Questions
How do I calculate a percentage of a number?
To calculate X% of Y, multiply Y by X and divide by 100. For example, 25% of 400 = (25 × 400) ÷ 100 = 100. In decimal form, convert the percentage to a decimal (25% → 0.25) and multiply: 400 × 0.25 = 100. Our tool does this instantly — just select "What is X% of Y?" mode, enter both numbers, and the result appears live.
What is the formula for percentage increase?
Percentage increase = ((New Value − Original Value) ÷ Original Value) × 100. For example, going from 80 to 100 is ((100 − 80) ÷ 80) × 100 = 25%. This formula is used for salary hikes, price changes, sales growth, and population increase. Use our "Percentage Increase" mode for instant calculation.
How do I calculate a discount on a product?
To calculate the discounted price: Original Price × (1 − Discount% ÷ 100). For example, a ₹1,200 item at 25% off costs ₹1,200 × 0.75 = ₹900. To find the discount amount alone, use Original Price × (Discount ÷ 100) — in this case, ₹300 saved. Our Discount Calculator mode shows both the final price and the amount saved.
How is GST calculated in India?
GST (Goods and Services Tax) in India is added to the base price. GST-inclusive price = Base Price × (1 + GST Rate ÷ 100). Standard GST rates are 5%, 12%, 18%, and 28%. For example, a ₹1,000 product with 18% GST costs ₹1,180 total, with ₹180 GST. Our GST Calculator mode handles both adding and removing GST (reverse calculation).
How do I calculate a tip at a restaurant?
Tip amount = Bill Amount × (Tip % ÷ 100). Total payment = Bill + Tip. In India, standard tips range from 5% to 15% depending on service. For example, a ₹2,000 bill with a 10% tip means ₹200 tip and ₹2,200 total. In the US, 18–22% is common; in Europe, 5–10% is standard. Our Tip Calculator mode computes both instantly.
How do I calculate my marks percentage?
Marks percentage = (Marks Obtained ÷ Total Marks) × 100. For example, if you scored 425 out of 500, your percentage is (425 ÷ 500) × 100 = 85%. This is used for school boards, universities, competitive exams, and scholarship applications. Use our Marks Percentage mode to see your result instantly.
What is the difference between percentage increase and percentage difference?
Percentage increase measures the change from one value to another relative to the original value — e.g., 80 to 100 = 25% increase. Percentage difference measures the average distance between two values relative to their average — e.g., 80 and 100 = 22.2% difference. Use percentage increase for growth metrics and percentage difference for comparisons where neither value is a "baseline".
How do I do reverse percentage calculation?
Reverse percentage finds the original number given a percentage of it. Formula: Value ÷ (Percentage ÷ 100). Example: If ₹300 represents 25% of a total, then the total = 300 ÷ 0.25 = ₹1,200. This is used for finding pre-tax prices, pre-discount costs, and pre-increase values. Our Reverse Percentage mode handles this effortlessly.
Why do percentages matter in everyday life?
Percentages appear in almost every financial decision: shopping discounts (flat 30% off), GST on purchases, salary increments, loan interest rates, investment returns, exam grades, and even nutritional information on food labels. As mathematician John Allen Paulos noted in Innumeracy, understanding percentages is a fundamental life skill. Our tool makes these calculations instant and error-free.
How do I calculate percentage without a calculator?
Useful mental shortcuts: (1) 10% of any number = move decimal one place left (10% of 250 = 25). (2) 5% = half of 10% (12.5). (3) 15% = 10% + 5% (25 + 12.5 = 37.5). (4) 25% = divide by 4. (5) 50% = divide by 2. For complex values, use our tool — it handles all edge cases including decimals and negative numbers.
Is my data safe with this percentage calculator?
Absolutely. All calculations run 100% in your browser using JavaScript. No data is transmitted to any server, stored in a database, or shared with third parties. You can even use the tool offline after loading the page once.
Is this percentage calculator free?
Yes — completely free, no signup, no watermark, no limits. Brought to you by Endeavour Marketing, a digital marketing agency in Pune, India.
What other free tools does Endeavour Marketing offer?
Explore our growing library of free utility and marketing tools: Age Calculator with Birthday Countdown, Meta Tag & SERP Preview Generator, Schema Markup (JSON-LD) Generator, UTM Campaign Link Builder, Email Signature Generator, QR Code Generator with Tracking, and many more.