Percentage Calculator
Calculate percentages instantly with three different calculation modes. Free, fast, and works offline.
How to Use the Percentage Calculator
This calculator offers three modes to cover every percentage calculation you might need:
- What is X% of Y? — Enter a percentage and a number to find the result. Example: What is 15% of 300? Answer: 45.
- X is what % of Y? — Enter two numbers to find what percentage the first is of the second. Example: 30 is what % of 120? Answer: 25%.
- Percentage Change — Enter an original value and a new value to find the percentage increase or decrease. Example: From 80 to 100 = 25% increase.
About Percentages
A percentage is a way of expressing a number as a fraction of 100. The word comes from the Latin per centum, meaning "by the hundred." Percentages are used everywhere in daily life — from calculating discounts and tips to understanding interest rates, tax, and statistics.
The basic percentage formula is: Result = (Percentage × Number) ÷ 100. For percentage change, the formula is: ((New - Old) ÷ Old) × 100. These formulas are the foundation of financial calculations, scientific analysis, and everyday math.
Frequently Asked Questions
Multiply the number by the percentage and divide by 100. For example, 25% of 200 = (200 × 25) / 100 = 50. You can also move the decimal point two places left: 25% becomes 0.25, then 0.25 × 200 = 50.
Use the formula: ((New Value - Old Value) / Old Value) × 100. A positive result means an increase, and a negative result means a decrease. For example, going from 80 to 100: ((100 - 80) / 80) × 100 = 25% increase.
To find what percentage X is of Y, divide X by Y and multiply by 100: (X / Y) × 100. For example, 30 is what percent of 150? (30 / 150) × 100 = 20%.
Yes, this calculator uses standard mathematical formulas and provides results with up to 4 decimal places. It is suitable for general financial calculations. For professional accounting or tax purposes, always verify with a qualified professional.