General

Percentage Change Calculator

Calculate the percentage increase or decrease between two numbers instantly. Enter an old value and a new value to see the percent change and absolute difference.

Percentage Change Calculator

Original (old) value

New value

Method

How this calculator works

Percentage change = ((new value − old value) / |old value|) × 100. A positive result is an increase; a negative result is a decrease.

Enter the original (old) value in the first field.
Enter the new value in the second field.
The calculator subtracts the old value from the new value to find the difference.
It divides that difference by the absolute value of the old value and multiplies by 100 to express the change as a percentage.

Examples

Worked examples

Real numbers, end-to-end results.

Old value 80, new value 100

= +25% (increase)

The value rose by 20, and 20 ÷ 80 × 100 = 25%.

Old value 200, new value 150

= −25% (decrease)

The value fell by 50, and 50 ÷ 200 × 100 = 25%.

Use cases

When to use it

Tracking price increases or discounts on products and services.
Measuring revenue, traffic, or performance growth between two periods.
Comparing before-and-after figures in reports and dashboards.
Calculating weight, score, or metric changes over time.

FAQ

Frequently asked questions

How do I calculate percentage change?

Subtract the old value from the new value, divide the result by the absolute value of the old value, then multiply by 100. The formula is ((new − old) / |old|) × 100.

What is the difference between percentage change and percentage difference?

Percentage change measures how much a value grew or shrank relative to its original (old) value, so the direction matters. Percentage difference compares two values relative to their average and is always positive.

Why can't I calculate percentage change from zero?

When the original value is zero, dividing by it is mathematically undefined. Any move away from zero represents an infinite percentage increase, so no finite percent change exists.

Is a negative result an increase or a decrease?

A negative percentage change means the value decreased, while a positive percentage change means it increased. This calculator also labels the direction for you.

Can percentage change be more than 100%?

Yes. If the new value is more than double the old value, the percentage increase exceeds 100%. For example, going from 50 to 150 is a 200% increase.