Find percentages, percentage change, discounts, and reverse percentages — four calculators in one, all instant and free.
Why this matters
Percentages are everywhere — sale prices, GST, tips, loan rates, salary hikes, exam scores — yet most of us reach for a calculator every single time because the formulas don't stick. This tool handles the four percentage problems you'll actually face: “What is X% of Y?”, “X is what % of Y?”, percent change (X to Y), and reverse percentage (working backwards from a final number).
The reverse one is the most useful and most rarely taught. When a price shows “₹2,400 after 20% off” and you want to know the original price, you can either dig out the formula or just punch it in here. Same for figuring out the pre-GST price on a bill, or the pre-discount price on a sale tag.
Best uses: shopping sales, calculating GST on bills, figuring out tip amounts, understanding discount stacks (20% off then 10% off is NOT 30% off), working out salary increments, and checking exam scores out of total marks.
X% of Y
X is what % of Y
% Change
Discount
What is X% of Y?
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X is what percent of Y?
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Percentage Change
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Discount Calculator
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You Save
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Final Price
Four Ways to Calculate a Percentage
"Percentage" questions usually come in one of four everyday shapes: finding a portion of a number, finding what percent one number is of another, finding the percentage change between two numbers, or working out a discounted price. This tool covers all four in one place so you don't need to remember which formula applies to which situation.
The Core Percentage Formula
X% of Y = (X ÷ 100) × Y. For example, 15% of 200 = (15 ÷ 100) × 200 = 30. Every other percentage calculation on this page is a variation of this same basic relationship, just solving for a different piece of the equation.
Percentage Change Explained
Percentage change measures how much a number has grown or shrunk relative to its starting value: ((New − Old) ÷ Old) × 100. A positive result means an increase, a negative result means a decrease. This is the calculation behind salary hikes, investment returns, and price changes over time.
Calculating a Discount
To find a discounted price, multiply the original price by the discount percentage to get the amount saved, then subtract that from the original price. A ₹1,500 item at 20% off saves you ₹300, bringing the final price to ₹1,200 — exactly what the Discount tab above calculates instantly.
Frequently Asked Questions
How do I calculate a percentage increase?
Use the % Change tab: enter the original (From) value and the new (To) value. A positive result shows the percentage increase; a negative result shows a decrease.
What's the difference between percentage and percentage points?
Percentage change is relative (e.g., going from 20% to 25% is a 25% relative increase), while a percentage point is the raw difference (5 percentage points). This distinction matters most in statistics, interest rates, and survey results.
How do I reverse-calculate the original price before a discount?
If you know the discounted price and the discount percentage, divide the discounted price by (1 − discount ÷ 100). For example, ₹1,200 at 20% off means the original price was ₹1,200 ÷ 0.8 = ₹1,500.
Can I use this for tip calculations?
Yes — the X% of Y tab works well for tips: enter your tip percentage as X and your bill total as Y to get the tip amount.
