Percentage Calculator (2026) – % of Number, % Change, % Difference & More
Find X% of a given number. Example: What is 15% of 800?
Calculate percentage increase or decrease from one value to another. Example: Price changed from ₹500 to ₹650.
Find the percentage difference between two values (symmetric — no base). Example: Difference between 80 and 120.
Find what percentage one number is of another. Example: 45 is what % of 180?
Find the original number before a percentage was applied. Example: After 20% increase, value is 1200 — what was original?
Calculate profit margin, markup percentage and profit amount. Used in business and retail pricing.
All Percentage Formulas Explained with Examples
Percentage is simply a way of expressing a number as a fraction of 100. The word “percent” comes from the Latin “per centum” meaning “out of 100.” Here are all six percentage formulas used in this calculator, explained clearly with examples.
1. Percentage of a Number
The most basic calculation — find X% of a given number.
Example: What is 18% of 2,500?
Result = (18 ÷ 100) × 2,500 = 0.18 × 2,500 = 450
Use case: GST calculation — 18% GST on ₹2,500 invoice = ₹450
2. Percentage Change (Increase or Decrease)
Measures how much a value has changed relative to its original value. Used for price changes, salary hike %, GDP growth etc.
Positive result = Increase | Negative result = Decrease
Example: Salary increased from ₹45,000 to ₹54,000
% Change = ((54,000 – 45,000) ÷ 45,000) × 100 = (9,000 ÷ 45,000) × 100 = +20%
Example 2: Price fell from ₹1,200 to ₹900
% Change = ((900 – 1,200) ÷ 1,200) × 100 = –25%
3. Percentage Difference
Measures the relative difference between two values without a “base” — both values are treated equally. Used when comparing two items of equal standing.
Example: Compare prices ₹800 and ₹1,200
|800 – 1,200| = 400 | Average = (800 + 1,200) ÷ 2 = 1,000
% Difference = 400 ÷ 1,000 × 100 = 40%
Note: % Difference (40%) ≠ % Change from 800 to 1,200 (50%). These are different calculations for different purposes.
4. What Percent is One Number of Another
Finds what percentage the first number is of the second. Used for exam marks, market share, completion percentage etc.
Example 1: Student scored 72 out of 120 marks
% = (72 ÷ 120) × 100 = 60%
Example 2: Company A has sales of ₹25 crore out of industry total ₹200 crore
Market Share = (25 ÷ 200) × 100 = 12.5%
5. Reverse Percentage
Find the original value before a percentage increase or decrease was applied. Very useful for finding MRP from discounted price, or pre-GST price from GST-inclusive price.
After % Decrease: Original = Final Value ÷ (1 – %/100)
Example 1: Product costs ₹1,180 inclusive of 18% GST. What is price before GST?
Original = 1,180 ÷ (1 + 18/100) = 1,180 ÷ 1.18 = ₹1,000
Example 2: After 25% discount, price is ₹750. What was MRP?
MRP = 750 ÷ (1 – 25/100) = 750 ÷ 0.75 = ₹1,000
6. Profit Margin vs Markup
Two different ways to express profit as a percentage — margin uses selling price as base, markup uses cost price as base.
Markup % = (Selling Price – Cost Price) ÷ Cost Price × 100
Example: CP = ₹600, SP = ₹900
Profit = ₹300
Margin = 300 ÷ 900 × 100 = 33.3% (on SP)
Markup = 300 ÷ 600 × 100 = 50% (on CP)
Same profit, different percentages. Retail uses margin; manufacturers use markup.
Quick Reference Percentage Tables
Common Percentage Values – Quick Reference
| Percentage | Fraction | Decimal | Of ₹1,000 | Of ₹5,000 | Of ₹10,000 |
|---|---|---|---|---|---|
| 1% | 1/100 | 0.01 | ₹10 | ₹50 | ₹100 |
| 5% | 1/20 | 0.05 | ₹50 | ₹250 | ₹500 |
| 10% | 1/10 | 0.10 | ₹100 | ₹500 | ₹1,000 |
| 12% | 3/25 | 0.12 | ₹120 | ₹600 | ₹1,200 |
| 15% | 3/20 | 0.15 | ₹150 | ₹750 | ₹1,500 |
| 18% | 9/50 | 0.18 | ₹180 | ₹900 | ₹1,800 |
| 20% | 1/5 | 0.20 | ₹200 | ₹1,000 | ₹2,000 |
| 25% | 1/4 | 0.25 | ₹250 | ₹1,250 | ₹2,500 |
| 28% | 7/25 | 0.28 | ₹280 | ₹1,400 | ₹2,800 |
| 30% | 3/10 | 0.30 | ₹300 | ₹1,500 | ₹3,000 |
| 50% | 1/2 | 0.50 | ₹500 | ₹2,500 | ₹5,000 |
| 75% | 3/4 | 0.75 | ₹750 | ₹3,750 | ₹7,500 |
Percentage Change Reference – Price Movements
| Old Price | New Price | Change | % Change |
|---|---|---|---|
| ₹100 | ₹110 | +₹10 | +10% |
| ₹100 | ₹120 | +₹20 | +20% |
| ₹100 | ₹80 | -₹20 | -20% |
| ₹500 | ₹600 | +₹100 | +20% |
| ₹1,000 | ₹750 | -₹250 | -25% |
| ₹50,000 | ₹60,000 | +₹10,000 | +20% |
Percentage Mental Math Tricks – Calculate Without Calculator
These tricks let you calculate most common percentages in your head within seconds — extremely useful for shopping, salary negotiations, tip calculations and quick checks.
1. The 10% Trick — Base of All Mental % Math
To find 10% of any number, simply move the decimal one place to the left (or divide by 10). Once you have 10%, all other percentages are easy:
- 10% of ₹3,500 = ₹350
- 5% = half of 10% = ₹175
- 20% = double of 10% = ₹700
- 15% = 10% + 5% = ₹350 + ₹175 = ₹525
- 25% = 10% + 10% + 5% = ₹875, or simply divide by 4 = ₹875
2. Flip the Numbers — 18% of 50 = 50% of 18
Percentages are commutative — A% of B = B% of A. So 18% of 50 = 50% of 18 = 9. This is useful when one of the numbers is easy to take a percentage of.
- 12% of 75 = 75% of 12 = 9
- 8% of 125 = 125% of 8 = 8 + 2 = 10
- 4% of 250 = 250% of 4 = 10
3. GST Calculation Shortcut
- 5% GST: Find 10%, halve it. ₹2,000 → 10% = ₹200 → 5% = ₹100
- 12% GST: Find 10% + 2%. ₹5,000 → ₹500 + ₹100 = ₹600
- 18% GST: Find 20% – 2%. ₹3,000 → ₹600 – ₹60 = ₹540
- 28% GST: Find 30% – 2%. ₹10,000 → ₹3,000 – ₹200 = ₹2,800
4. Discount Shortcut
- 10% off ₹1,499: ₹1,499 – ₹150 = ₹1,349 (approximately)
- 20% off: Multiply by 0.8 (or remove 20%): ₹2,500 × 0.8 = ₹2,000
- 25% off: Divide by 4, then subtract: ₹1,200 / 4 = ₹300 off → ₹900
- 50% off: Simply halve it
Real Life Uses of Percentage Calculations in India
1. GST Calculation
GST in India uses percentage — 5%, 12%, 18%, and 28%. When a shopkeeper says price is ₹1,180 inclusive of 18% GST, reverse percentage gives you the base price: ₹1,180 ÷ 1.18 = ₹1,000. When filing GST returns, CGST and SGST are each half the total rate (9% + 9% for 18% GST).
2. Salary Hike and Increment
A 15% salary hike on ₹45,000 basic = ₹6,750 increment = new salary ₹51,750. To compare two job offers, calculate the percentage increase from current CTC to offered CTC using the % change formula.
3. Bank Interest and Loan EMI
Personal loan interest rates are expressed as percentages per annum. A 12% p.a. loan on ₹5 lakh = ₹60,000 annual interest = ₹5,000/month interest (approximate). EMI also includes principal repayment, calculated using compound interest formula.
4. Exam Marks and Grades
If a student scores 378 out of 500 marks: (378 ÷ 500) × 100 = 75.6%. For CBSE, ICSE, and board exams, percentage is the primary metric for college admissions. Use the “What % of” calculator tab for quick marks percentage.
5. Mutual Fund Returns (CAGR)
When a mutual fund gives 12% CAGR, it means ₹1 lakh grows to ₹3.1 lakh in 10 years — % change = 210%. For calculating year-wise returns, use our Compound Interest Calculator.
6. Profit and Loss in Business
A retailer buys goods at ₹800 and sells at ₹1,000: Profit = ₹200. Profit % (on CP) = 200/800 × 100 = 25% markup. Profit Margin (on SP) = 200/1,000 × 100 = 20%. Both are correct — just different bases. Use the Margin & Markup tab for business calculations.