Percentage Change Calculator

Calculate percentage increase/decrease, reverse changes, or compounding multi-step percentage changes.

Calculate the percentage increase or decrease from one value to another.

From (Original)

To (New Value)

Percentage Change

+25%

Absolute difference: +30

SummaryA change from 120 to 150 is a +25% change

Formula & Steps

Formula: ((New - Old) / |Old|) × 100

Steps: ((150 - 120) / |120|) × 100 = (30 / 120) × 100 = 25%

Understanding Percentage Change and Compounding

Percentage change measures the relative growth or shrinkage between an initial value and a final value. For a single step, it is calculated as ((New − Old) ÷ |Old|) × 100.

When dealing with multiple sequential percentage changes, they compound rather than add up linearly. For example, a +10% increase followed by a -10% decrease does not bring you back to 100% — it results in 99% of the starting value (a net -1% change). This calculator handles the compounding math automatically.

Built and maintained by Meet Shah · Last updated 1 August 2026

What this tool is used for

Expressing a rise or fall between two figures as a percentage.
Comparing growth across two periods of different absolute size.
Working out how far a value has moved from a baseline.
Checking a reported percentage against the two underlying numbers.
Expressing a reduction as a saving rather than a difference.

Frequently Asked Questions

How is percentage change calculated?: (new − old) ÷ |old| × 100. Dividing by the ABSOLUTE value of the old figure keeps the sign meaning 'direction of movement' even when the starting value is negative — a loss narrowing from −80 to −40 reads as +50%, an improvement, rather than the −50% you would get by dividing by −80.
Why is a change from zero rejected?: Because the divisor is the starting value, and any increase from zero is infinitely large in relative terms. Percentage change is only defined against a non-zero base. When your series genuinely starts at zero, report the absolute change instead — the relative version has nothing to be relative to.
Do sequential percentage changes add up?: No, they compound. +10% followed by −10% leaves 99% of the original — a net −1%, not zero — because the decrease applies to the larger intermediate figure. The multi-step tab chains the factors properly, which is why a series of monthly percentages cannot simply be summed into an annual one.
What does the reverse mode solve for?: Either end of the relationship. Give it a starting value and a percentage to get the final figure, or a final value and the percentage applied to get back to the original. The second is the one people get wrong by hand: reversing a 25% increase means dividing by 1.25, not subtracting 25%.
Is percentage change the same as percentage point change?: No. If a conversion rate moves from 2% to 3%, that is a rise of one percentage point and a 50% relative increase. Headlines routinely swap the two, and the gap between them grows as the base shrinks — which is why small-base metrics look so dramatic when reported the relative way.

Common errors and gotchas

Using the wrong value as the base, which changes both the size and the story of the change.
Confusing a percentage change with a percentage-point change, which are different quantities.
Reversing a percentage increase by subtracting the same percentage, which never returns the original.
Computing a change from a base of zero, which is undefined rather than infinite.
Chaining percentage changes additively, when they compound.