Percentage Increase / Decrease Calculator

This calculator helps you quickly calculate the percentage increase or decrease between two values.

It is widely used in finance, ecommerce, pricing, analytics, and everyday calculations.

Understanding percentage change is essential for tracking growth, comparing values, and making better decisions.

Whether you're analysing sales performance, price changes, or investment returns, this tool provides instant and accurate results.

Calculate percentage change

Understanding your result

A positive result means an increase, while a negative result means a decrease.

The percentage is always calculated relative to the original value, not the new value.

This makes it a powerful way to compare changes over time or between values.

How the calculation works

Formula: ((New − Old) ÷ Old) × 100

The calculator measures the difference between the two values and expresses it as a percentage of the original value.

Why percentage change matters

Examples

Example 1:
£100 → £120 = 20% increase

Example 2:
£80 → £60 = 25% decrease

Example 3 (Business):
Sales increase from £5,000 to £6,500 = 30% growth

Example 4 (Discount):
£50 reduced to £40 = 20% decrease

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Frequently asked questions

How do I calculate percentage increase?

Subtract old from new, divide by old, multiply by 100.

What is percentage decrease?

Same formula but result is negative.

Can you calculate from zero?

No, division by zero is not possible.