How is percentage calculated?

Percentage = (Part / Whole) × 100. For example, if 25 is 50% of 50, then (25/50) × 100 = 50%.

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

Divide the first number by the second number, then multiply by 100. For example, 20 is what percent of 80? (20/80) × 100 = 25%.

How do I calculate percentage change?

Percentage change = ((New Value - Old Value) / Old Value) × 100. A positive result indicates an increase, negative indicates a decrease.

What is the difference between percentage and percent?

Percentage is the rate or proportion per hundred, while percent (%) is the symbol used to represent it. They're often used interchangeably in everyday language.

How do I add or subtract a percentage?

To add: Original × (1 + Percentage/100). To subtract: Original × (1 - Percentage/100). For example, adding 20% to 100: 100 × 1.20 = 120.

Can percentages be greater than 100%?

Yes, percentages can exceed 100% when the part is larger than the whole. For example, if sales increase from $50 to $150, that's a 200% increase.

Percentage Calculator

Calculate percentages, find what percent one number is of another, or calculate percent changes. Perfect for discounts, taxes, tips, and everyday calculations.

Calculator

Result

Percent: -
Value: -
Result: -

Formula & Guide

Formulas

R

What is X% of Y?

Result = (X / 100) × Y

Calculate percentage of a value

%

X is what % of Y?

Percentage = (X / Y) × 100

Find what percent one number is of another

Δ

Percent Change

Change = ((New - Old) / Old) × 100

Calculate percentage increase or decrease

Formula Variables

X

Part or Percentage

The percentage value or the part being compared

Y

Whole or Base

The total value or the base number being compared against

%

Percentage

A ratio expressed as a fraction of 100

Step-by-Step Scenario

Example Scenario

Percentage

20%

Base Value

150

1

Convert Percentage to Decimal

Convert 20% to decimal: 20 ÷ 100 = 0.20

Always convert percentage to decimal form for calculation

2

Multiply by Base Value

Result = 0.20 × 150

= 30

Additional Examples

Discount Calculation

Original Price: $100

Discount: 25%

Discount Amount

$100 × 0.25 = $25

Final Price

$100 - $25 = $75

Percent Change

Old Value: $50

New Value: $75

Change

(($75 - $50) / $50) × 100

Result

50% increase

Characteristics of Percentages

Universal Application

Percentages are used everywhere: discounts, taxes, tips, interest rates, statistics, and everyday calculations.

Easy Comparison

Percentages make it easy to compare values of different scales by expressing them as parts per hundred.

Business Essential

Critical for business calculations including profit margins, sales growth, market share, and financial analysis.

Simple Conversion

Easy to convert between percentages, decimals, and fractions: 25% = 0.25 = 1/4.

Important Notes

Percentages are always expressed as parts per hundred, so 50% means 50 out of 100.
When calculating percentage of a value, convert the percentage to decimal first (divide by 100).
Percent change can be positive (increase) or negative (decrease) depending on whether the new value is greater or less than the old value.
Percentages greater than 100% are possible when the part exceeds the whole (e.g., 150% of original).
Always be careful with percentage points vs. percentages - a 5 percentage point increase is different from a 5% increase.

Frequently Asked Questions

Find answers to common questions about percentage calculations.