CAC and LTV calculator
What a customer costs, what a customer is worth, and whether the gap between them is big enough.
Runs entirely in your browser. Nothing you paste is uploaded or stored.
Acquisition cost on the left, lifetime value on the right. The ratio between them is the number investors ask about.
Salaries, agency fees, software. Leaving these out is what makes CAC look better than it is.
Fill in the order values on the left to get lifetime value and the ratio.
What this tool does
It calculates what a customer costs you, estimates what a customer is worth, and puts the two side by side — with the payback figure that turns the ratio into something you can act on.
Two fields do most of the work and are the ones usually skipped. Sales and tooling cost adds the people and software behind acquisition, which is where CAC quietly doubles. Gross margin converts lifetime value from revenue into money you actually keep.
The three numbers, in order of usefulness
Payback is first. It tells you how many orders it takes before a customer has paid for their own acquisition. Everything after that point is profit; everything before it is a loan you are extending to your growth.
The ratio is second. Three to one is the conventional target, and it is a floor rather than an aspiration. Below one to one you are buying customers who will never repay their cost, which is not a growth problem but an arithmetic one.
CAC on its own is last, because in isolation it means nothing. A €400 acquisition cost is disastrous for a €30 product and cheap for a €12,000 annual contract.
A caution about lifetime value
LTV is a forecast dressed as a fact. It assumes customers keep behaving the way past customers did, which is exactly what changes when a business scales its acquisition into a broader, colder audience. Treat a rising CAC alongside a stable LTV assumption as the first sign that the assumption has stopped being true.
Questions
What belongs in customer acquisition cost?
Everything spent to get the customer, not only the media. Salaries of the people running acquisition, agency fees, creative production, the tools they pay for. Ad-spend-only CAC is the most common way a business talks itself into believing acquisition is profitable.
What is a good LTV to CAC ratio?
Three to one is the widely used benchmark for a subscription business: below it there is not enough left to fund product and overhead, and far above it usually means you are underspending on growth rather than being disciplined.
How should I estimate lifetime value?
Average order value times the number of orders a customer actually makes, times gross margin. The margin step matters — revenue-based LTV overstates the number by exactly the cost of your product, which is how a 3:1 ratio turns out to be 1.2:1.
Why does the payback figure matter more than the ratio?
Because a ratio says nothing about when the money arrives. A 5:1 ratio that takes eighteen months to materialise still needs eighteen months of cash. Payback tells you how many orders it takes to get back to zero.
Is this suitable for ecommerce as well as SaaS?
Yes. For ecommerce, orders per customer is repeat purchase rate over the period you care about. For subscriptions it is the number of billing cycles before churn.