What is a Percentage? (Beginner Friendly Explanation)

Percentage is one of the most widely used mathematical concepts in everyday life. It simply represents a number out of 100. For example, 25% means 25 out of 100. Whether you are calculating discounts, GST, tax, marks, interest, salary hike, or profit/loss — percentages are used everywhere.

This free Percentage Calculator helps you solve the three most common percentage problems:

• 1) What is X% of Y?
• 2) X is what percent of Y?
• 3) Percentage increase or decrease between two numbers

1) What is X% of Y? (Formula & Example)

The formula to find the percentage of a number is:

Result = (X / 100) × Y

Example:

What is 20% of 150?
(20 / 100) × 150 = 30 ✔ Answer = 30

2) X is what percent of Y?

This tells you the percentage relationship between two numbers.

Percentage = (X / Y) × 100

Example:

45 is what percent of 90?
(45 / 90) × 100 = 50% ✔ Answer = 50%

3) Percentage Increase or Decrease

This is useful for salary hikes, price changes, marks improvement, stock price movement, etc.

Percentage Change = ((New − Old) / Old) × 100

Example:

You increased from 200 to 240.
((240 − 200) / 200) × 100 = 20% ✔ Answer = 20% increase

Where Are Percentages Used in Daily Life?

• Shopping discounts (30% OFF, 50% SALE)
• GST and tax calculations
• Salary hike percentage
• School exam results
• Loan interest rate
• Profit and loss calculation
• Stock market and crypto changes

Benefits of Using This Free Percentage Calculator

• ✔ Fast and accurate results
• ✔ No login required
• ✔ Mobile-friendly
• ✔ 100% free tool
• ✔ Perfect for students, accountants, business owners, shoppers, and teachers

Percentage Calculator Examples (Quick Reference)

Question	Answer
10% of 500	50
25% of 1200	300
40 is what percent of 200?	20%
Increase from 80 to 100	25% increase
Decrease from 250 to 200	20% decrease

Frequently Asked Questions (FAQ)

1. How do you calculate percentage manually?

You divide the part by the whole and multiply by 100.

2. How to find percentage increase?

Use the formula: ((New − Old) / Old) × 100

3. How to calculate 20% of a number?

Multiply the number by 0.20.

4. Can I calculate GST percentage using this?

Yes, you can calculate GST% or any tax % using the same formula.

5. Is this percentage calculator free?

Yes, Quick Invoice Hub offers this tool 100% free with no login.