Free CAC and LTV Calculator: Payback and LTV:CAC Ratio
CAC is only half of an acquisition decision. Pair the cost to acquire a new customer with the revenue and contribution that customer can generate, then check how many orders it takes to recover the investment.
Estimated payback: 1.67 orders. This is a planning model, not a cohort forecast; retention, refunds and timing can change the result.
How this free tool works
Calculate customer acquisition cost, revenue LTV, contribution LTV, payback orders and the LTV:CAC ratio from your own numbers. The result is designed to be transparent: you can see the inputs, the formula and the assumptions instead of receiving a black-box score.
CAC = sales and marketing spend ÷ new customers. Revenue LTV = AOV × orders per customer. Contribution LTV = revenue LTV × gross margin. LTV:CAC = contribution LTV ÷ CAC.
Best for
- DTC founders deciding whether a paid channel can scale
- Growth teams comparing blended acquisition economics
- Operators who want payback context instead of a vanity CAC
Frequently asked questions
What is the CAC formula?+
CAC equals the sales and marketing spend used for acquisition divided by the number of new customers acquired in the same period.
Should LTV use revenue or profit?+
Revenue LTV is useful for a quick view, but contribution LTV is safer for payback because it accounts for gross margin before comparing with CAC.
Is a 3:1 LTV:CAC ratio guaranteed to be healthy?+
No. Ratios are directional. Cohort retention, cash timing, refunds, channel mix and the quality of the margin assumption can change the decision.
References and methodology
We use primary documentation where available and treat calculators as planning aids, not guarantees. Check the linked source when a platform changes its rules.
- Shopify: Customer acquisition cost
Explains CAC, included acquisition costs and how to pair it with LTV and margin.
- Shopify: What is a good LTV:CAC ratio?
High-authority context for interpreting lifetime value against acquisition cost.
Turn this answer into a repeatable growth workflow.
Use the free result as your starting point, then move the next campaign, creative or growth decision into GrowthGPT when the work becomes repetitive.