Coupon Stacking: How to Compare Multiple Discounts Correctly
Two discounts do not always add together in the obvious way. Their order and eligible subtotal determine the real combined saving.
Why two 20% discounts are not 40% off
If the second 20% discount applies after the first, a $100 item becomes $80 and then $64. The combined reduction is $36, or 36%, because the second discount applies to a smaller base.
Percentage first or dollars first?
On a $100 cart, 20% off followed by $10 off produces $70. Ten dollars off followed by 20% off produces $72. Retailers set the order, so use their checkout sequence rather than choosing the more favorable calculation yourself.
Discount order changes the result
These calculations use the same $100 starting cart.
| Scenario | First discount | Second discount | Result |
|---|---|---|---|
| 20%, then $10 | $100 → $80 | $80 → $70 | Final total $70 |
| $10, then 20% | $100 → $90 | $90 → $72 | Final total $72 |
| 20%, then 10% | $100 → $80 | $80 → $72 | Combined discount is 28% |
Where free shipping fits
Free delivery usually removes a separate shipping line rather than reducing merchandise. A coupon can push the eligible subtotal below the delivery threshold, which means a larger merchandise discount may unexpectedly restore the shipping charge.
- Record merchandise after discounts.
- Check the threshold definition.
- Add tax and shipping last unless the terms specify otherwise.
- Compare loyalty credit separately if it is earned for a future purchase.
Distinguish instant savings from future value
Points, store credit, and cashback that arrive later do not reduce today’s payment. Discount their value if they expire, require another order, or can only be spent in restricted increments.
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