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Percentage Increase/Decrease Calculator

Calculate percentage increase, decrease, percent change, and reverse values instantly.

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What is the Percentage Increase/Decrease Calculator?

The Percentage Increase/Decrease Calculator helps you quickly compare an original value and a new value to find the exact percent change. It shows whether the result is an increase, decrease, or no change, along with the absolute difference and multiplier.

Use it for price changes, salary growth, sales performance, discounts, inventory changes, and any situation where you want to understand relative change instead of only the raw difference.

Unlike basic calculators that only return one number, this tool also gives reverse and what-if values so you can see how the same change behaves from both directions.

How it works

Enter the old value and the new value.

It then calculates the absolute difference, detects whether the result is an increase or decrease, and shows a multiplier for fast comparison.

The tool also provides reverse values so you can estimate what the original number would be after applying the same percentage increase or decrease.

If the old value is zero, percentage change cannot be calculated because division by zero is not allowed.

Examples

From 80 to 100

Find the percent increase and the absolute change.

Old value: 80, New value: 100
Change: 20, Percent change: +25%

From 150 to 120

Find the percent decrease and direction.

Old value: 150, New value: 120
Change: -30, Percent change: -20%

Frequently asked questions

What is the formula for percentage increase?

Percentage increase is calculated by subtracting the old value from the new value, dividing the result by the old value, and multiplying by 100.

What is the formula for percentage decrease?

Percentage decrease is calculated by subtracting the new value from the old value, dividing by the old value, and multiplying by 100.

Can this calculator handle both increase and decrease?

Yes. If the new value is greater than the old value, it shows an increase. If the new value is smaller, it shows a decrease.

Why do you need the old value to be non-zero?

Because percentage change divides by the old value. If the old value is zero, the calculation is undefined.

What is the difference between absolute change and percentage change?

Absolute change is the raw difference between two numbers. Percentage change shows that difference relative to the old value.

Can I use this for prices, sales, and salary changes?

Yes. It works for any two numeric values where you want to measure relative growth or reduction.

What does the multiplier mean?

The multiplier shows how many times the new value is compared to the old value. For example, 1.25 means the value is 25% higher than before.

Does this tool show reverse calculations?

Yes. It includes reverse and what-if values so you can understand how the same percentage change affects the original number.

Is the Percentage Increase/Decrease Calculator free?

Yes, it runs entirely in your browser with no server calls.

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