When you know the original price and the sale price, subtract them to find the saving. Divide that saving by the original price, then multiply by 100. The original price is the comparison base; dividing by the sale price answers a different question.
Calculate a 300-to-225 price reduction
Open the Tolibox discount percentage calculator. Enter 300 as the original price and 225 as the reduced price. The saving is 75 and the discount is 25%.
You can check the result in three lines:
- Saving: 300 − 225 = 75.
- Fraction saved: 75 ÷ 300 = 0.25.
- Percentage saved: 0.25 × 100 = 25%.
To reverse-check, enter 300 and 25% into the discount calculator. The final price should return to 225.
Keep the comparison fair
Use matching prices: the same product size, package quantity, and treatment of extra charges. Comparing a single item with a multipack can produce a percentage that is mathematically correct but commercially misleading.
An original price of zero cannot be used as the denominator. If the new price is higher than the original, there is no ordinary discount: you are comparing a price increase. Do not present a negative saving as a retail reduction.
The percentage describes the difference between the two numbers entered. It does not verify that the original price was previously charged or that the offer is the best available.
Why not divide 75 by 225?
That calculation measures the saving relative to the new price. It produces about 33.33%, not the discount from the original price.
Can I use decimal prices?
Yes. Keep the two prices in the same currency and round the final percentage only as much as your comparison requires.
Check both the percentage and the amount saved before deciding whether an offer fits your budget.