What's the formula for percentage change?

((new value − old value) / old value) × 100 — a negative result means a decrease.

Can I use negative numbers?

Yes, for the percentage-change calculator; the other two assume positive values since "15% of −200" is rarely what people mean.

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Percentage calculator

Three common percentage calculations in one place.

What is X% of Y?

What is % of ?

X is what percent of Y?

is what % of ?

Percentage change from X to Y

From to

How it works

Covers the three percentage calculations people actually search for separately: finding X% of a number, figuring out what percent one number is of another, and calculating the percentage change between two values — each with its own formula rather than one generic calculator that's hard to map to your actual question.

FAQ

What's the formula for percentage change?: ((new value − old value) / old value) × 100 — a negative result means a decrease.
Can I use negative numbers?: Yes, for the percentage-change calculator; the other two assume positive values since "15% of −200" is rarely what people mean.

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