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Percentage Change Calculator

Instantly find the percentage increase or decrease between any two numbers.

Calculate Percentage Change

The starting or "before" value

The ending or "after" value

What Is Percentage Change?

Percentage change measures how much a value has grown or shrunk relative to its original size. A positive result is an increase; a negative result is a decrease. It is one of the most widely used calculations in finance, science, and everyday life — from comparing prices to tracking weight loss.

Percentage change math calculation Data analytics growth chart showing percentage increase Business finance showing increase and decrease trends

The Formula

Percentage Change = ((New Value − Original Value) ÷ |Original Value|) × 100

The vertical bars around Original Value mean you use its absolute value (ignore the minus sign if it is negative). The result is expressed as a percentage.

Step-by-Step Examples

Example 1 — Price Increase

A jacket cost $80 last year and costs $100 this year.

((100 − 80) ÷ 80) × 100 = (20 ÷ 80) × 100 = +25%

The price increased by 25%.

Example 2 — Weight Loss

Someone weighed 200 lb and now weighs 175 lb.

((175 − 200) ÷ 200) × 100 = (−25 ÷ 200) × 100 = −12.5%

Body weight decreased by 12.5%.

Example 3 — Sales Growth

Monthly revenue went from $4,200 to $5,880.

((5880 − 4200) ÷ 4200) × 100 = (1680 ÷ 4200) × 100 = +40%

Revenue grew by 40%.

Common Percentage Change Reference Table

OriginalNewChangeDirection
100125+25%Increase
10075−25%Decrease
50100+100%Doubled
20050−75%Decrease
1,0001,500+50%Increase
80800%No change

Frequently Asked Questions

What is the formula for percentage change?

Percentage change = ((New Value − Original Value) ÷ |Original Value|) × 100. A positive result means an increase; a negative result means a decrease.

What is the difference between percentage change and percentage difference?

Percentage change compares a new value to an original value with direction (increase or decrease). Percentage difference compares two values symmetrically, without a direction, using the average of the two values as the denominator.

What happens if the original value is zero?

Percentage change is undefined when the original value is zero, because you cannot divide by zero. If your original value is 0, consider using the absolute difference instead.

Can the percentage change exceed 100%?

Yes. For example, if a price goes from $50 to $150, that is a 200% increase. Percentage change has no upper or lower limit.

How do I reverse a percentage change?

To reverse a known percentage change back to the original value, divide the new value by (1 + percentage/100). For example, if $120 is a 20% increase, the original value is 120 ÷ 1.20 = $100.

Is a −50% change the same as a +50% change in reverse?

No. A 50% decrease followed by a 50% increase does not return to the original. Example: 100 → −50% → 50 → +50% → 75. The two moves are not symmetrical.

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