Percentage Calculator

Calculate percentages, percentage increase, percentage decrease, and percentage of a number. Perfect for math homework, business calculations, and everyday percentage problems.

Select Calculation Type

What is X% of Y?

Percentage (%) *

Number *

X is what percent of Y?

Part (X) *

Whole (Y) *

Percentage change from X to Y

Original Value (X) *

New Value (Y) *

Percentage difference between X and Y

First Value (X) *

Second Value (Y) *

Calculation Results

Enter values to calculate

How the Percentage Calculator Works

Choose Calculation Type

Select from four calculation types: percentage of number, what percent, percent change, or percentage difference.

Enter Your Values

Input the required numbers based on your selected calculation type. All fields support decimal values.

Get Instant Results

View the calculated result with detailed explanations and step-by-step breakdown of the calculation.

Understand the Formula

Learn the mathematical formula used for each calculation type to understand the underlying math.

Frequently Asked Questions

How do I calculate what percentage one number is of another?

To find what percentage X is of Y, use the formula: (X ÷ Y) × 100. For example, to find what percentage 25 is of 100: (25 ÷ 100) × 100 = 25%.

What's the difference between percentage change and percentage difference?

Percentage change measures the change from an original value to a new value, while percentage difference compares two values without considering which is the "original." Percentage change can be positive or negative, while percentage difference is always positive.

How do I calculate percentage increase and decrease?

Percentage change formula: ((New Value - Original Value) ÷ Original Value) × 100. If the result is positive, it's an increase. If negative, it's a decrease. For example, from 50 to 75: ((75-50) ÷ 50) × 100 = 50% increase.

Can I use this calculator for business and financial calculations?

Yes! This calculator is perfect for business applications like calculating profit margins, sales growth, discount rates, tax percentages, and financial ratios. All calculations use precise decimal arithmetic for accuracy.

What if I get a negative percentage?

Negative percentages are normal in percentage change calculations and indicate a decrease. For example, if a stock price drops from $100 to $80, the percentage change is -20%, meaning a 20% decrease.