What Is Percent Change? Simple Definition and Examples

Every growth rate, raise, markdown, and poll swing you read about is a percent change. Here is what the number actually means, in plain English.

Percent change expresses how much a value grew or shrank, relative to where it started. A price rising from $80 to $100 changed by 25 percent, because the $20 move is one quarter of the starting $80. Positive means growth, negative means decline, and the starting value is what makes the percentage meaningful.

The plain-English definition

Percent change answers one question: how big was the move, compared to where it started? Take the difference between the new value and the old value, express that difference as a fraction of the old value, and write it as a percentage. The formula is ((new - old) / old) x 100, but the idea is simpler than the symbols: it is the change, sized up against the starting point.

That "compared to where it started" part is what makes percent change useful. A $20 increase means something different on an $80 price than on a $400 price. The percentage adjusts for the context automatically, which is why growth rates, raises, and discounts are all quoted in percent.

How to read a percent change

Positive means it grew. +25 percent is a 25 percent increase. The new value is bigger than the old one.

Negative means it shrank. -20 percent is a 20 percent decrease. The minus sign only indicates direction; drop it when you say the word "decrease."

Zero means no change. The new and old values are the same.

100 percent means doubled. A 100 percent increase takes any value to twice itself. A -100 percent change takes it to zero.

Beyond 100 percent means more than doubled. A 200 percent increase triples the starting value ($50 to $150). There is no upper limit.

Percent change vs absolute change

Absolute change is the raw difference: $100 to $80 is a $20 absolute change. Percent change is that difference relative to the starting value: the same $20 is a 20 percent move from $100, but a 25 percent move from $80. The two numbers answer different questions, and good analysis uses both. The percentage shows the scale of the move; the dollars show its weight.

A shop whose sales rise from $1,000 to $3,000 can claim 200 percent growth, which sounds dramatic. A rival growing from $100,000 to $150,000 posts a less impressive 50 percent. In dollars, the rival gained $50,000 while the first shop gained $2,000. Percent change without absolute change can mislead, especially from small bases.

Where you meet percent change every day

Money: salary raises, price markdowns, stock gains and losses, inflation rates, and rent increases are all percent changes. Our percent increase guide and percent decrease guide work through the money examples step by step.

Business: revenue growth, customer churn, conversion-rate changes, and budget variances are reported as percent changes so that teams of different sizes can be compared fairly.

Public life: poll swings, election results, unemployment rates, and test-score changes are percent changes. Watch for the percentage-point trap here: a poll moving from 42 to 46 percent rose 4 percentage points, which is a 9.5 percent change relative to its start. Our percentage points vs percent guide explains the distinction.

Try it with your own numbers. Enter any two values and see the percent change instantly, with the calculation shown.

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Percent change questions, answered

What does a 25 percent change mean?

It means the new value is 25 percent larger than the old value, relative to the starting point. An $80 price rising to $100 is a 25 percent change, because the $20 increase is one quarter of the original $80.

What does a negative percent change mean?

A negative percent change means the value went down. Negative 20 percent is read as a 20 percent decrease. The minus sign indicates direction, and the number indicates size.

What is the difference between percent change and absolute change?

Absolute change is the raw difference: $100 to $80 is a $20 absolute change. Percent change is that difference relative to the starting value: the same $20 move is 20 percent of $100 but 25 percent of $80. Absolute change shows size, percent change shows scale.

When is percent change misleading?

Percent change misleads when the starting value is small or zero. Going from 1 sale to 5 sales is a 400 percent increase that says almost nothing, and percent change is undefined when the starting value is zero. Always pair big percentages with the absolute numbers.

What is percent change used for?

Percent change is used to compare growth and decline anywhere: salary raises, price changes, stock performance, sales growth, inflation, test scores, and election polling. Any time you want to know how big a move is relative to its starting point, percent change is the tool.

What Is Percent Change?