Coupon Value Calculator
The minimum spend does the work.
The minimum spend does the work. The minimum spend is what makes a coupon work; it converts a discount into a basket-size lever.
Coupon cost
$10.00
$12.00 of basket uplift it buys
The minimum spend is what makes a coupon work; it converts the discount into a basket-size lever. Set it below the normal basket and the coupon is a pure giveaway to people already buying.
How the Coupon Value Calculator works
The minimum spend is what makes a coupon work; it converts a discount into a basket-size lever. Set below the normal basket, a coupon is a pure giveaway to people already buying.
Also known as: what is my coupon worth · promo code value · voucher saving calculator
The cost of a coupon is not its face value
A £10 coupon costs £10 only on orders that would not have happened otherwise. On orders that would have happened anyway, it costs £10 of pure margin for nothing.
Which means the real cost per incremental order is the total discount given divided by the incremental orders, and that figure is frequently several times the face value.
If a campaign issues 1,000 coupons, 200 are redeemed, and 60 of those orders were genuinely incremental, then £2,000 of discount bought 60 orders at £33 each. That is the acquisition cost to compare against other channels, not the £10 on the coupon.
Estimating incrementality
The clean method is a holdout: withhold the coupon from a random sample of the target group and compare purchase rates. The difference is the incremental effect and everything else is subsidy.
Most sellers do not do this, because withholding an offer from customers feels like leaving money on the table. It is the only reliable way to know whether the offer is working, and the cost of the holdout is trivial against the cost of running an ineffective campaign indefinitely.
Where a holdout is impractical, the next best is comparing the redeeming cohort's behaviour against a matched non-redeeming cohort. It is confounded by self-selection, since people who redeem coupons were more likely to buy anyway, and it is better than nothing.
Where coupons leak
Public coupon sites are the largest leak. A code intended for an email list appears on a voucher aggregator within hours, and it is then applied by customers who were already at the checkout and were searching for a code in another tab.
That last behaviour is the specific damage: a customer who was going to buy at full price pauses at checkout, searches for a code, finds one, and the sale completes at a discount. The coupon field itself creates this behaviour.
Mitigations exist and each has a cost. Unique single-use codes prevent sharing and complicate distribution. Removing the coupon field except when a code is present in the URL removes the prompt and confuses customers who have a legitimate code. Neither is free, and both are cheaper than the leak in most catalogues.
Which customers should get one
The customers most responsive to coupons are frequently the least valuable: price-sensitive, low repeat rate, and likely to wait for the next offer rather than buy at full price.
Targeting matters more than the offer. A coupon to a lapsed customer who has not bought in a year is buying reactivation. The same coupon to an active customer who buys monthly is buying nothing and training them to wait.
Which is why segmented offers outperform broadcast ones by a wide margin on contribution, even when they look worse on redemption rate. A campaign with a 4% redemption to lapsed customers can be worth more than one with 20% redemption to active ones.
The training effect
The longest-running cost of couponing is that it teaches customers a discount is always available. A business that discounts every month has customers who never buy at full price, and reversing that takes considerably longer than establishing it.
The signal is measurable: the proportion of orders using a discount code. If it is climbing year on year, the customer base is being trained, and the eventual full-price sales rate will not recover simply by stopping.
The alternatives are structural rather than promotional. Value framed through bundles, thresholds and loyalty rather than through codes achieves similar conversion effects without establishing that the list price is negotiable. That is a harder programme to run and it does not degrade over time in the same way.
Where to go next
The Coupon Value question rarely arrives on its own. These are the ones that usually come with it:
- Promo Code ROI Calculator — Most of the discount goes to people buying anyway.
- Spend and Save Calculator — Each tier has to earn its place.
- Dollar Off Calculator — A fixed amount shifts the mix downward.
- Etsy Fee Calculator — Every Etsy fee on one sale, itemised.
Not financial advice. Marketplace fees change, and they vary by country, plan and seller status. Every rate here is an editable default, not a quoted price, check the platform's current fee schedule before you price a product against it. This is not tax or business advice.
Frequently asked questions
Where should the minimum spend sit?
Above the current average order value, close enough that reaching it means adding one item rather than two. Too far above and nobody uses the coupon.
How much should a coupon be worth?
Less than the contribution on the basket uplift it produces. If reaching the threshold adds £18 of contribution, a coupon worth more than that loses money on every redemption.
Should coupons expire?
Yes, urgency drives redemption and an open-ended coupon becomes a permanent price cut. Two to four weeks is a common window.
Do coupons attract the wrong customers?
Public codes do, because they reach people who would never have paid full price and who churn quickly. Targeted codes to specific segments perform far better.
Related calculators
Promo Code ROI Calculator
Most of the discount goes to people buying anyway.
OpenSpend and Save Calculator
Each tier has to earn its place.
OpenDollar Off Calculator
A fixed amount shifts the mix downward.
OpenEtsy Fee Calculator
Every Etsy fee on one sale, itemised.
Open