Formula
Final value = value × (1 + p₁) × (1 + p₂) × (1 + p₃). Equivalent change = (1 + p₁) × (1 + p₂) × (1 + p₃) − 1.
Example
A $100 price that goes up 10% and then down 10% ends at $99, not $100: the equivalent change is −1%. To undo a 1% drop, you need a 1.0101% increase.
Finding the original value
If you know the price after the changes, divide by the same factor. A $99 price that came from +10% and −10% was originally $100. The result also shows this reverse calculation.
For a single percentage of a value, use the percentage calculator.
Frequently asked questions
Why don’t percentages add up?
The second change is applied to the new value, not the original. 10% of $110 is more than 10% of $100.
What are two 20% discounts worth?
0.8 × 0.8 = 0.64, so a 36% total discount, not 40%.
See also
Results are estimates for information only and are not financial, legal or medical advice. Rates, taxes and fees vary — confirm with a professional or your lender.