Price increase formula
If a price rises from 80 to 96, the increase is 16. 16 ÷ 80 × 100 = 20%, so the new price is 20% higher than the old price.
Price decrease formula
If a price falls from 250 to 200, the reduction is 50. 50 ÷ 250 × 100 = 20%.
Examples
| Old price | New price | Change | Percentage |
|---|---|---|---|
| 100 | 110 | +10 | 10% increase |
| 120 | 138 | +18 | 15% increase |
| 200 | 150 | −50 | 25% decrease |
| 80 | 60 | −20 | 25% decrease |
Use the original price as the denominator. Dividing by the new price answers a different question.
Add a known percentage to a price
If the rate is already known and you need the new price, multiply the old price by 1 + rate. To add 8% to 500, multiply 500 × 1.08 = 540. To reduce 500 by 8%, multiply by 0.92 = 460.
Find the original price from the final price
If 120 is the price after a 20% increase, divide 120 by 1.20 to get the original 100. If 120 is the price after a 20% discount, divide 120 by 0.80 to get the original 150.
Markup, margin and price increase are not identical
Markup compares profit with cost. Margin compares profit with selling price. Price increase compares a new price with an old price. A 25% markup on cost does not equal a 25% profit margin, so use the formula that matches the business question.
Percentage points versus percent change
If a discount rate changes from 10% to 15%, that is an increase of 5 percentage points. Relative to the original 10% rate, it is a 50% increase. State clearly whether you mean percentage points or percentage change.
Practical uses
Price percentage change is useful for supplier quotes, rent changes, product pricing, inflation comparisons, salary adjustments, cost estimates and discount checks. For comparisons across time, make sure the old and new prices refer to the same quantity, specification and tax basis.
Frequently asked questions
How do I calculate a price increase percentage?
Subtract old price from new price, divide by old price and multiply by 100.
How do I calculate a price decrease percentage?
Subtract new price from old price, divide by old price and multiply by 100.
How do I add 15% to a price?
Multiply the original price by 1.15.
Is price increase the same as markup?
Not always. Price increase compares new price with old price; markup usually compares selling price with cost.
Enter your own values, keep the assumptions visible and use this guide to understand the formula behind the result.