What Is a Percentage Calculator?
A percentage calculator is a free online tool that helps you calculate percentages quickly and accurately — without needing to remember formulas or do manual math. Whether you are finding a discount at a shop, calculating a grade, figuring out tax, or tracking investment returns, a percentage calculator gives you the right answer in seconds.
Our percentage calculator offers six different calculation modes in one tool — making it the most versatile free percentage calculator available. Every result includes the formula with your actual numbers plugged in, so you always understand how the answer was reached.
Calculate shopping discounts, tax, tips & more with our free percentage calculator
How to Calculate a Percentage — Complete Guide
Type 1: What is X% of a Number?
This is the most common percentage calculation — used for discounts, tips, tax, and more. The formula is:
Result = (Number × Percentage) ÷ 100
📘 Example — Shopping Discount
A jacket costs Rs. 5,000 and is on 35% sale.
Discount = (5,000 × 35) ÷ 100 = Rs. 1,750
Final price = 5,000 − 1,750 = Rs. 3,250
Type 2: X is What Percent of Y?
Use this when you have a part and a whole and want to express their relationship as a percentage.
Percentage = (Part ÷ Whole) × 100
📘 Example — Exam Score
You scored 72 out of 90 marks.
Percentage = (72 ÷ 90) × 100 = 80%
Type 3: Reverse Percentage — X is Y% of What?
Use this when you know the result and the percentage but need to find the original whole number.
Whole = Part ÷ (Percentage ÷ 100)
📘 Example — Finding Original Price
A product is on sale at Rs. 800 after a 20% discount. What was the original price?
Original = 800 ÷ (1 − 0.20) = 800 ÷ 0.80 = Rs. 1,000
Type 4: Percentage Change (Increase or Decrease)
This formula tells you by what percentage a value has gone up or down. Positive result = increase, negative = decrease.
% Change = ((New − Old) ÷ Old) × 100
📘 Example — Salary Raise
Your salary went from Rs. 50,000 to Rs. 60,000.
% Change = ((60,000 − 50,000) ÷ 50,000) × 100 = +20% increase
Type 5: Percentage Difference
Unlike percentage change, this compares two values without a "direction" — it uses their average as the base. Useful when comparing two things of equal status (e.g. two products, two cities).
% Diff = (|V1 − V2| ÷ ((V1 + V2) ÷ 2)) × 100
Type 6: Add or Subtract a Percentage
Perfect for adding tax, applying a markup, or subtracting a discount from a number in one step.
Result = Number × (1 + % ÷ 100) for adding
Result = Number × (1 − % ÷ 100) for subtracting
Pro Tip: To find the original price before a percentage was added (e.g. tax-inclusive price), use the Reverse Percent mode. Enter the final price as "Part" and the tax rate as "%". Our calculator finds the pre-tax amount instantly.
Percentage vs. Percentage Points — What's the Difference?
Many people confuse these two terms, but they mean very different things:
- Percentage change — A relative change expressed as a percentage of the original. If inflation goes from 5% to 7%, that is a 40% increase in inflation.
- Percentage points — An absolute difference between two percentages. If inflation goes from 5% to 7%, that is a 2 percentage point increase.
Our Percentage Change calculator tells you the relative change (%), while Percentage Difference gives you a neutral comparison between two values.
Percentage change calculator — track salary raises, investment growth & price changes
Common Percentage Conversions
- 10% of any number = divide by 10
- 25% of any number = divide by 4
- 50% of any number = divide by 2
- 75% of any number = multiply by 3, then divide by 4
- 1% of any number = divide by 100
- To convert a decimal to %: multiply by 100 (e.g. 0.35 = 35%)
- To convert a fraction to %: divide top by bottom, multiply by 100 (e.g. 3/4 = 75%)
