How to use the coupon vs percent off calculator
- Enter the price before any offer.
- Enter the dollar coupon, such as $15 off, and the percent off offer, such as 15% off.
- If the coupon has a minimum spend, enter it. The coupon only counts when the price reaches that amount.
- Read which offer saves more, the price with each, and the price at which the two are equal.
Formula
Coupon price = price - coupon (when the price meets any minimum spend)
Percent off price = price x (1 - percent off / 100)
Break-even price = coupon / (percent off / 100)
Coupon first, then percent = (price - coupon) x (1 - percent / 100)
Percent first, then coupon = price x (1 - percent / 100) - coupon
Below the break-even price the dollar coupon saves more. Above it the percent off saves more.
$15 off versus 15% off an $80 item
The coupon brings $80 down to $65. Fifteen percent of $80 is $12, so the percent offer brings it down to $68. The coupon saves $3 more, and it is worth 18.75% of the price.
The two offers are equal at $15 / 15% = $100. On a $120 purchase the percent offer saves $18, which beats the $15 coupon. If both could be used on the $80 item, taking the coupon first leaves $55.25 and taking the percent first leaves $53.00.
Where the crossover comes from
A dollar coupon is worth the same on any price, while a percent discount grows with the price. That is why a small purchase favors the coupon and a large purchase favors the percent. The break-even price is the point where the two amounts are equal.
If the coupon needs a minimum spend, the tool checks the price against it. Under the minimum, the coupon is treated as not applying, and the percent offer is the only saving.
Stacking offers
Some stores let you use both a coupon and a percent off, and the order they apply them changes the total. Taking the percent off first and the dollar coupon second saves more than the reverse, because the coupon is not shrunk by the percent.
The table is only for comparison, since many stores allow one offer per order. To see a discount with tax use the discount calculator, and to value a rebate that arrives later use the rebate calculator.
Assumptions and limits
- The coupon cannot take more than the price off.
- The percent off applies to the whole price shown.
- The stacking table assumes a store allows both offers, which many do not.
- Taxes, shipping, rewards and other fees are not included.
Frequently asked questions
Is $10 off better than 20% off?
It depends on the price. They are equal at $50. Below $50 the $10 coupon saves more, and above $50 the 20% saves more.
How do I find the price where two offers are equal?
Divide the dollar coupon by the percent as a decimal. For a $15 coupon and a 15% offer that is $15 / 0.15 = $100.
Does the order of discounts matter?
Yes when both apply. Applying the percent off first and subtracting the dollar coupon afterward leaves a lower price than the other order, because the coupon is not reduced by the percent.
What if the coupon has a minimum purchase?
Enter it. When the price is below the minimum, the coupon does not apply and the tool compares nothing but the percent off against no coupon.