Discount Deal Comparator
Quick answer: A bigger percent off does not always mean a better deal — compare final prices, not percentages. Deal A at $120 with 30% off costs $84.00, while Deal B at $100 with 15% off costs $85.00, so Deal A wins by $1.00. Enter any two prices and discount rates above to see each final price, the savings, and the winner with the margin instantly.
Two sales, one product — which is actually cheaper? This discount deal comparator puts two price-and-discount offers side by side and shows each final price, the dollars saved, the effective percent off, and the winner with the exact margin.
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Your results
Exact arithmetic, rounded to the cent. Prices compared before sales tax.
How to use this calculator
Enter the original price and the percent off for each deal. The final prices, savings, and the winner update instantly as you type.
For example, $120 at 30% off gives a final price of $84.00 (you save $36.00), while $100 at 15% off gives $85.00 (you save $15.00). Deal A wins by $1.00 — the margin is the plain difference between the two final prices.
How it works
Final price = price × (1 − discount ÷ 100). Dollars saved = price − final price. The winner is the deal with the lower final price, and the margin is the higher final price minus the lower one.
Reference data
| Conversion | Rule |
|---|---|
| Percent → decimal | Divide by 100: 30% = 0.30, 15% = 0.15 |
| Final price | price × (1 − discount ÷ 100) |
| Dollars saved | price − final price, equivalently price × (discount ÷ 100) |
| Effective percent off | 100 × saved ÷ price (equals the discount you entered) |
| Winner's margin | | final price A − final price B | |
Source: basic percentage arithmetic — no external data is consumed; every figure is computed live from your inputs.
Method & sources
For each deal the calculator converts the percent discount to a decimal by dividing by 100, multiplies the original price by (1 − that decimal) for the final price, and subtracts to get the dollars saved. The deal with the lower final price wins, and the margin is the absolute difference of the two final prices. All figures are exact arithmetic rounded to the nearest cent — not estimates. The comparison is before sales tax, since tax applies equally to both deals at the same register.
- No external data sources are used on this page — every figure is computed live from your inputs with the formulas above.
Worked example
Deal A: $120 × (1 − 30 ÷ 100) = $120 × 0.70 = $84.00 (saved $120 × 0.30 = $36.00). Deal B: $100 × (1 − 15 ÷ 100) = $100 × 0.85 = $85.00 (saved $100 × 0.15 = $15.00). Effective discounts are 30% vs 15%. Winner: Deal A, by $85.00 − $84.00 = $1.00.
Frequently asked questions
How do I compare two discount deals?
Compute each deal's final price as price × (1 − percent off ÷ 100). The deal with the lower final price wins, even when the percent off looks smaller: $120 at 30% off is $84.00, while $100 at 15% off is $85.00, so the bigger sticker price with the bigger discount wins by $1.00.
Does a bigger percent off always mean a better deal?
No. Percent off applies to the starting price, so a smaller percent off a much lower price can nearly tie: $100 at 15% off costs $85.00, only $1.00 more than $120 at 30% off ($84.00). Always compare final prices, not percentages.
Should I include sales tax when comparing deals?
The calculator compares pre-tax prices. If both deals are bought in the same place, tax shifts both by the same percentage and the winner stays the same; add tax to the final price with our sales tax calculator to get your true checkout total.
How do I compare a buy-one-get-one deal with a percent-off deal?
Treat it as a percent off the combined original price: a buy-one-get-one-free offer on a $60 item is 50% off the two-item $120 total, which you can enter directly into this comparator.
Is the winner's margin exact?
Yes — every figure is exact arithmetic rounded to the nearest cent. Final price = price × (1 − discount ÷ 100), and the margin is the simple difference between the two final prices.