Which is cheaper?
Which is the better deal: 25% more or 25% off?
The Simple Answer
25% off is the better deal. A pack with 25% more costs you 20% less per ounce. A 25% price cut costs you 25% less per ounce.
They sound alike, but they are measured against different starting points. Take a box of cereal that normally holds 12 ounces and costs $4.00, which is 33.3 cents an ounce.
A 12-ounce box that costs $4.00
Usual price: $4.00 ÷ 12 = 33.3 cents per ounce
25% more: 15 ounces for $4.00. $4.00 ÷ 15 = 26.7 cents per ounce, which is 20% cheaper.
25% off: 12 ounces for $3.00. $3.00 ÷ 12 = 25.0 cents per ounce, which is 25% cheaper.
Why the two are not the same
Twenty-five percent more of 12 ounces is 3 extra ounces. That is a quarter of what you started with, but only a fifth of what you end up holding, because 3 is one fifth of 15. The price per ounce falls by that smaller share. A price cut, on the other hand, comes straight off the price you were paying.
A rule that works for any offer
| The offer | Price per unit falls by |
|---|---|
| 10% more | 9.1% |
| 25% more | 20% |
| 33.3% more (a third extra) | 25% |
| 50% more | 33.3% |
| 100% more (two for the price of one) | 50% |
Read the table the other way and you can match any extra with a discount. A third extra free is the same saving per ounce as 25% off. Two for the price of one is the same as 50% off.
When the comparison gets harder
Offers do not always come with tidy percentages, and the sizes may be in different units. The safe method is the one used above: work out the price per ounce, per sheet or per whatever you actually use, and compare those.
Better Deal Calculator: Enter two offers and see which costs less per unit, and by how much.
Unit Price Calculator: Turn a price and a size into a price per ounce, per gram or per sheet.