📊 Percentage Change Calculator

Work out the percentage increase or decrease between two numbers, plus reverse percentages and a worked price-change example.

From / old value

To / new value

Reverse percentage — find the original amount before a % change

Result after change

Change applied (%)

increase decrease

Formula: change % = (new − old) ÷ old × 100. For a reverse percentage, divide by the multiplier: original = result ÷ (1 ± p/100). A change from 25 to 30 is a 20% increase — and from 30 back to 25 it's a 16.7% decrease, because the base differs.