Percentage Calculator

Solve for any part of a percentage problem, compare two values, or find a percentage increase or decrease.

What is P% of V?

Enter any two of the three values — leave the one you want solved blank.

Percentage Difference

Find the percentage difference between two values.

Percentage Increase / Decrease

Find the result of increasing or decreasing a value by a percentage.

The one formula behind all of this

Every percentage problem boils down to the same equation: P × V1 = V2, where P is the percentage (as a decimal), V1 is the value being modified, and V2 is the result. Which of the three you're solving for just depends on which two you already know — that's what the first calculator above does automatically.

Difference vs. change

"Percentage difference" and "percentage change" sound similar but answer different questions. Percentage difference treats two values symmetrically — there's no "before" or "after," just a comparison. Percentage change (increase/decrease) is directional: it measures how much a specific starting value grew or shrank.

A common mistake: a 50% increase followed by a 50% decrease doesn't return you to the original value. $100 up 50% is $150; $150 down 50% is $75 — not $100. Percentage changes don't cancel out symmetrically.

Common questions

Why is percentage difference always positive?

It uses the absolute value of the difference between the two numbers, so it doesn't matter which value is "first" — the result reflects how far apart they are, not which one is bigger.

How do I convert a percentage to a decimal?

Divide by 100 — 35% becomes 0.35. This is what the calculators above do internally before running the underlying math.

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