Small Business Tool Lab · Calculators
A campaign can produce healthy-looking revenue and still fail its first-order cost test. Before increasing the budget, count distinct new paying customers and reconcile the spending needed to acquire them. Coupon uses are not the denominator.
The reconciled result: $18 becomes $31.50
Hypothetical campaign, one period and U.S. dollars: 60 coupon uses belong to 48 distinct customers; eight already bought before. That leaves 40 new customers. Assume $3,600 in their net first-order revenue after discounts and refunds, excluding sales tax.
| Acquisition spending | Amount |
|---|---|
| Ads | $720 |
| Creative | $180 |
| Allocated labor | $300 |
| Allocated tools | $60 |
| Total | $1,260 |
Ad-only CAC is $720 ÷ 40 = $18. Fully allocated CAC is $1,260 ÷ 40 = $31.50. With $2,400 in separate variable fulfillment costs, first-order contribution is $1,200. After acquisition spending, the modeled result is −$60, before other fixed overhead and taxes. It is not accounting net profit.
Reconcile customers before costs
Join order records to a consistent customer identifier. Remove duplicate identities, distinguish prior customers and declare how cancellations and refunds affect the cohort. Revenue, costs and the customer count must use the same cohort and period.
Shopify’s marketing-report documentation explains that attribution models assign channel credit differently, and order reports can include canceled, pending and unpaid orders. Reconcile to paid customer records instead of summing platform conversion counts.
Use the same cost boundary twice
Allocate creative, labor and tools once. Do not add wages again if an agency invoice already includes them, or count acquisition labor inside fulfillment too. Cash spending and allocated staff time answer different budget questions; label both.
Enter your own inputs below. The initial numbers reproduce the hypothetical case. If the interactive tool is unavailable, use total acquisition cost ÷ new customers and net revenue − variable costs − acquisition cost.
Decide whether the next test is justified
This worksheet fits a bounded campaign with usable customer and order records. It fits poorly when long sales lags or missing identity data make today’s denominator incomplete. Zero new customers means CAC is undefined, not zero.
A negative first-order result does not prove a lifetime loss. It does mean future repeat contribution would need evidence. Attribution is not causal lift, and an assumed lifetime value should not rescue a weak test. Review returns, repeat behavior and your cash limit before spending again.
Frequently asked questions
Should referrals have zero CAC?
Include referral rewards and attributable work when those costs exist.
Can I compare campaigns with different sales cycles?
Use matched observation windows or clearly mark cohorts that have not matured.
Is the calculator a tax-profit estimate?
No. It isolates selected campaign and first-order costs; other overhead and tax treatment remain separate.
What if the customer count changes after refunds?
Apply your declared cohort rule and recompute both revenue and the denominator consistently.
Source notes
Official documents linked beside the claims were checked October 18, 2026. Hypothetical figures are not quotes or forecasts.
Illustrative photo: Bench Accounting benchaccounting · CC0 1.0. Original photo shown without the supplied thumbnail overlay; no endorsement implied.
