Percentage Calculator

Calculate percentages instantly — find what percent of a number is, compute percentage change, increase, decrease, and more.

1 What is X% of Y?

What is % of ?
Enter values above
Formula: (X / 100) — Y

2 X is what % of Y?

is what % of ?
Enter values above
Formula: (X / Y) — 100

3 Percentage Change

From to
Enter values above
Formula: ((New - Old) / Old) — 100

4 Increase / Decrease by %

%
Enter values above
Formula: Value — (1 — Percent/100)

How to Use the Percentage Calculator

  1. What is X% of Y? — Enter a percentage and a number to find the result. Example: What is 15% of 200? Answer: 30.
  2. X is what % of Y? — Find what percentage one number is of another. Example: 25 is what % of 200? Answer: 12.5%.
  3. Percentage Change — Calculate the percentage increase or decrease between two values. Example: From 80 to 100 = 25% increase.
  4. Increase/Decrease by % — Apply a percentage increase or decrease to any number. Example: 200 increased by 15% = 230.

All calculations are performed instantly in your browser. No data is sent to any server. Results can be used for finance, shopping discounts, tips, grades, statistics, and more.

Understanding Percentages

A percentage represents a fraction of 100. The word comes from Latin "per centum" meaning "by the hundred." Percentages are used everywhere in daily life: shopping discounts, tax rates, exam scores, interest rates, statistics, and nutrition labels. Understanding how to calculate percentages is an essential life skill.

Common Percentage Formulas

What is X% of Y? Multiply Y by X/100. Example: 15% of 200 = 200 × 0.15 = 30. X is what % of Y? Divide X by Y, multiply by 100. Example: 30 is what % of 200? (30/200) × 100 = 15%. Percentage change: ((New - Old) / Old) × 100. Example: Price went from $80 to $100: ((100-80)/80) × 100 = 25% increase.

Real-World Uses

Percentages are essential in finance (interest rates, returns on investment), education (grades and scores), health (body fat percentage, nutritional daily values), retail (discounts and markups), and data analysis (growth rates, market share). Mastering percentage calculations helps you make better financial decisions, understand statistics in the news, and evaluate deals while shopping.