Ecommerce customer economics
Ecommerce LTV & Max CAC Calculator
Connect repeat purchases and gross margin to the customer acquisition cost your store can actually afford.
✓ Customer metrics stay on this device✓ No signup✓ Instant results
Customer economics
Lifetime contribution and acquisition limit
Results are deterministic scenarios based only on your inputs.
Maximum CAC at target ratio$88.00
The model has positive contribution value. Compare the maximum CAC with actual channel costs.
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Customer metrics stay on this device
AOV, margin, repeat purchase and CAC values are calculated locally and are never sent to 321Kit.
Method
How ecommerce LTV and max CAC are calculated
This simple contribution model keeps revenue, margin and acquisition assumptions visible.
1. Lifetime orders and revenue
Purchase frequency is scaled by the customer lifespan, then multiplied by average order value.
Lifetime revenue = AOV × purchases per year × lifespan months ÷ 12 2. Contribution LTV
Gross margin converts lifetime revenue into the amount available before acquisition cost.
Contribution LTV = lifetime revenue × gross margin 3. Maximum CAC
Divide contribution LTV by your chosen target ratio to set an acquisition ceiling.
Maximum CAC = contribution LTV ÷ target LTV:CAC ratio Why this is not a forecast
The calculator holds frequency, lifespan and margin constant. It cannot predict churn, cohorts or future customer behavior.
Use one margin definition
Use a gross or contribution margin that consistently includes the same product, fulfillment, refund and fee costs across channels.
FAQ
Ecommerce LTV and CAC FAQ
What does this calculator call LTV?
It reports contribution LTV: modeled lifetime revenue multiplied by your margin. It is not gross lifetime revenue or a cohort forecast.
How is maximum CAC calculated?
Contribution LTV is divided by the target LTV:CAC ratio you enter. A higher target ratio produces a lower acquisition ceiling.
Why is a zero CAC ratio shown as unavailable?
Dividing by zero would create an infinite ratio, which is not useful for a decision. CAC payback is zero when acquisition cost is zero.
Should I always target 3:1?
No. The calculator does not impose an industry benchmark. Choose a ratio that matches your cash cycle, risk and accounting definition.
Does 321Kit store customer metrics?
No. Inputs and calculations stay in your browser and are not uploaded.