Prepared by Finflo. Our methodology · Editorial policy
Compare two offers on the same item
Suppose the same item has a list price of $120 at two shops. Shop A offers 25% off. Shop B offers 20% off followed by a $10 coupon. Assume the item, delivery charges, and return terms are identical, and exclude tax for this first comparison. The larger advertised percentage does not settle which offer costs less.
At Shop A, the discount is 120 × 0.25 = $30, leaving $90. At Shop B, 120 × 0.80 = $96, then the coupon reduces the price to $86. Shop B is $4 cheaper even though its advertised percentage is smaller. Its total saving is $34, or about 28.33% of the original $120.
In the discount calculator, use Calculate with Original price 120, Percentage discount 25, Additional fixed discount 0, and Sales tax after discount 0 for Shop A. Change the percentage to 20 and the fixed discount to 10 for Shop B. Keeping the original price and tax assumption unchanged isolates the effect of the offer.
| Offer | After percentage discount | After coupon | Total saving |
|---|---|---|---|
| Shop A: 25% off | $90.00 | $90.00 | $30.00 |
| Shop B: 20% off, then $10 | $96.00 | $86.00 | $34.00 |
Coupon order can change the answer
Now keep Shop B’s numbers but change the order. Subtracting the $10 coupon first gives $110; taking 20% off that smaller base leaves $88. Applying the percentage first leaves $86. The $2 difference is 20% of the $10 coupon: the coupon itself gets reduced when the percentage is applied afterward.
Finflo’s main discount mode applies the percentage first and the fixed discount second. If the offer uses the reverse order, enter the post-coupon price of 110 as Original price, use a 20% discount, and leave the fixed discount at zero. Check whether a coupon applies to the entire basket or only eligible items before treating either result as a checkout total.
Successive percentages multiply
An offer of 20% off followed by another 10% off leaves 80% of the original price, then 90% of that remainder. For $120, the calculation is 120 × 0.80 × 0.90 = $86.40. The combined discount is 28%, not 30%. Adding the percentages would incorrectly predict a price of $84.
Use 1 − (1 − a) × (1 − b) for the combined discount when a and b are decimal fractions. Two pure percentage discounts give the same result in either order before rounding, but a fixed coupon does not have that property. If a shop rounds each line or each discount to cents, compare against its itemized receipt.
Recover the original price from a sale price
If an item costs $80 after a 20% reduction, $80 represents 80% of the original. Divide by 0.80 to recover $100. Adding 20% to $80 gives $96 because that calculation uses the smaller sale price as its base.
The increase needed to return from $80 to $100 is $20 ÷ $80 = 25%. This is why a 20% fall and a 20% rise do not cancel. In Reverse a percentage change, enter Final value 80 and Signed change −20. A 100% reduction leaves zero regardless of the original price, so it cannot be reversed to a unique amount.
Keep tax and delivery assumptions visible
For an illustrative 8% tax applied to the discounted price, Shop A totals 90 × 1.08 = $97.20 and Shop B totals 86 × 1.08 = $92.88. The difference becomes $4.32. If Shop A offers free delivery and Shop B charges $6 for delivery, Shop B’s combined cost becomes $98.88, making it $1.68 more expensive overall.
The 8% rate is an example, not a rate lookup or a statement about how a particular coupon is taxed. Finflo applies your entered tax rate after both discounts and excludes shipping. Use the actual checkout’s treatment of coupons, taxes, and delivery when you compare a real purchase.
Check the comparison before choosing
Write down the original price, the order of discounts, which items qualify, and the final payable amount. An apparently better discount can lose its advantage when minimum-spend rules or delivery costs change. For a fair comparison, use the same quantity and product variant at each shop.
These scenarios were constructed for this guide. The reference below explains the underlying percentage arithmetic; it does not supply the shop offers or determine their terms.