Percentage Change Calculator — Find Percent Increase / Decrease

Percentage Change Calculator

Calculate percent increase or decrease between two numbers. Get instant results, difference, and a clear visual comparison.

Step 1: Original Value

About original value

The starting point or old value. It can be any positive or negative number. If it’s zero, we’ll show an error message.

Step 2: New Value

About new value

The updated or later value. The calculator will compute the relative change from the original.

Your Percentage Change Result

Calculation
Formula & Examples
Common Uses

Percentage Change

+20.0%
increase from original
Original Value
100
New Value
120
Difference
+20
Absolute Change
20

Percentage Change Formula

Formula

% change = ( (New – Original) / |Original| ) × 100

We use the absolute value of the original to handle negative numbers correctly.

Step-by-Step Example

StepCalculationResult
1. Subtract120 – 10020
2. Divide by original20 / 1000.2
3. Multiply by 1000.2 × 10020%
4. DirectionPositive = increase+20%

Where Percentage Change Is Used

Finance: stock returns, inflation
Sales: price changes, discounts
Health: weight loss/gain, metrics
Education: grade improvements

Quick tip

A positive percentage means an increase, negative means a decrease. If original is zero, percentage change is undefined (division by zero).

Need More Help with Percentages?

Explore our suite of math and finance calculators. From tip calculators to compound interest, we’ve got you covered.

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