percentage change, percentage difference, markup, discount and reverse-percentage calculators

Percentage calculations without mental gymnastics

Solve percentage change, discounts, markups, differences and reverse percentages with explicit formulas.

Tools

Calculate relative change from an old value to a new value.

Find a chosen percentage of a value.

Apply a percentage discount to an original price.

Apply a percentage markup to a cost.

Recover the base value when the final value equals a known percentage of it.

A change in a rate can be described in two different ways.

A discount removes a fraction of the original price.

Markup uses cost as the base, while margin uses selling price.

Reverse percentages divide by the rate instead of multiplying by it.

Rounding too early can change later calculations.