Customizer apps usually bill usage one of two ways: a percentage of every custom sale, or a fee per personalized item. Every vendor we checked in October 2026 used one or the other rather than both, though some tools bill per seat instead. Pick the model yours uses, then replace the defaults with your own numbers.
- Personalized items / month — count personalized items specifically. Generic ecommerce orders that never run through the designer are out of scope.
- Average order value — used to turn a percentage fee into money. On the per-item model it does not affect the result.
- Their monthly subscription — the subscription line from your vendor's own pricing page, not a review site. Divide an annual contract by 12.
- How they charge for usage — the choice between the two models above. Switching it resets the rate, because a figure like 1.7 means one thing as a percentage and something very different as a per-item fee.
- The rate itself — either the percentage of order value or the charge per personalized item. If your vendor bills per product rather than per item, multiply by your average products per order — team-kit orders make this much larger than people expect.
Why there is only one usage fee
This calculator used to add a percentage and a per-item fee together, with both switched on by default. When we checked the major vendors' published pricing in October 2026, each of them charged one model or the other, not both — so adding the two produced a number higher than any of those products would actually bill. That is not a comparison worth showing you. It is one fee now. If you have found a vendor that genuinely charges both, enter the larger one and treat the result as conservative.
The arithmetic, in full
There is nothing hidden in the calculation, so you can check it against your own invoice:
- Their yearly cost = (monthly subscription × 12) + usage fees × 12, where usage is either items × order value × percentage or items × per-item fee
- Our yearly cost = $348 — $29 a month, at every volume
- What you keep = the difference, shown per year, per month, and over three years
Typical rates
From vendors' own pricing pages, checked in October 2026. This is a snapshot of the vendors we looked at, not a survey of the whole category, and rate cards change — check your own vendor's page rather than relying on these:
- Percentage model: 1.5% – 1.95% of each custom sale, usually falling as your plan tier or volume rises.
- Per-item model: $0.10 – $1.00 per personalized item, again falling with volume, sometimes after a small free allowance.
- Subscription underneath it: roughly $49 – $300 a month before any usage fee at all.
What this calculator does not tell you
It compares subscription and usage fees, and nothing else. It leaves out implementation, migration, the staff time either tool costs you to run, and payment-processing fees you pay whichever platform you are on. It also floors the saving at zero, so it will never show you a negative number to flatter us — if your current tool is genuinely cheaper at your volume, this will show zero rather than tell you so. Work that case out by hand.
Three worked examples
The vendor figures below are illustrative inputs, not any particular company's published prices — put your own quote into the calculator. They show how the shape of the bill changes with volume:
- A small shop. 100 items a month at $35, against a $49 subscription on the per-item model at $0.50. Their cost is $49 + $50 = $99/month, or $1,188 a year. Ours is $348. You keep about $840 a year. Real, but not yet the thing that decides your stack.
- A growing brand. 300 items at $40, a $99 subscription, 1.7% of each sale. Their cost is $99 + $204 = $303/month, or $3,636 a year. Ours is $348. You keep roughly $3,288 a year — close to $10,000 over three years.
- At scale. 2,000 items at $45, a $199 subscription, 1.5% of each sale. Their cost is $199 + $1,350 = $1,549/month, or $18,588 a year. Ours is still $348, because nothing in our pricing moves with your volume. That gap is the whole argument: on a usage model your software bill grows fastest in exactly the months your business is doing best.