Marketing and acquisition
LTV to CAC ratio calculator
The LTV to CAC ratio compares what a customer is worth against what they cost to win. Divide lifetime value by acquisition cost. Both figures have to be measured on the same basis or the ratio is meaningless.
Contribution, not revenue
Fully loaded, including salaries and fees
The formula
- Lifetime value
- The contribution an average customer delivers over their whole relationship with you, not the revenue. Take the revenue figure from the lifetime value calculator and multiply it by your gross margin. Skipping that step is the single most common reason this ratio reports a healthy business that is not one.
- Acquisition cost
- The fully loaded cost of winning one customer, including salaries, agency fees, tools, and content, divided by the customers that spending actually won. The CAC calculator covers what belongs in it. A media-only figure here paired with a revenue lifetime value above produces a ratio wrong in both directions at once.
A worked example
The outdoor gear brand has a 1,000 lifetime value and a 167 acquisition cost, which is 6:1. The rule of thumb says 3:1, so the brand is at twice the healthy level, and the sensible reading of a ratio that high is that acquisition is being underfunded. The meeting ends with a decision to increase the budget.
The 1,000 was revenue. At a 25 percent gross margin the contribution is 250, and the ratio is 1.5:1. The brand is not at twice the healthy level, it is at half of it, and it is buying growth at a price the business cannot support.
Notice what the error did. It did not merely overstate the position, it reversed the recommendation. A revenue-based ratio told the brand to spend more at exactly the moment a contribution-based one would have told it to stop and fix retention or margin first. That inversion is why this page insists on the basis before it discusses the benchmark.
When to use it
The ratio answers one question well: can this business afford the way it is growing. It is the standard test behind budget decisions, investor conversations, and any argument about whether to scale a channel, because it collapses the two numbers that matter into a single figure a room can act on.
It is most useful by channel and by cohort rather than blended. A company sitting at 3:1 overall is frequently running one channel at 6:1 and another at 1:1, and the blend keeps the second one funded. Splitting the ratio is usually the fastest route to a budget reallocation that pays for itself.
Track the direction as much as the level. A ratio drifting down while spending holds steady means either acquisition is getting more expensive or customers are leaving sooner, and the two have completely different fixes. Neither is visible in revenue for several quarters.
Where it misleads
A high ratio is not the good news it appears to be. At 6:1 or 8:1 on a contribution basis, the usual explanation is not remarkable efficiency but underinvestment. Customers worth six times what they cost are customers you should be buying far more of, and a ratio that high generally means growth is being left on the table. The healthy zone has a ceiling as well as a floor.
The ratio says nothing about when the money arrives. A 3:1 where the cost is recovered in four months and a 3:1 where it takes two years are different businesses, and the second one has to finance the gap out of working capital. Payback period is the companion measure, and for anything cash-constrained it is the more urgent of the two.
Both inputs are estimates and the ratio inherits every weakness in each of them while looking more precise than either. Lifetime value rests on an assumed lifespan that nobody can measure directly. Acquisition cost rests on a judgement about which customers the spending actually won. A clean number like 3.2:1 conceals both.
The three to one benchmark came out of subscription software, where margins are high and retention is measurable, and it assumes a contribution basis. Carrying it unchanged into ecommerce, services, or anything with a heavy cost of delivery imports assumptions that do not hold. Use it as a starting point for a conversation rather than a pass mark.
Frequently asked
What is a good LTV to CAC ratio?
Three to one is the widely used target, measured with lifetime value on a contribution basis rather than revenue. Below it, growth is being bought too expensively. Well above it usually indicates underinvestment in acquisition rather than exceptional efficiency.
Should the ratio use revenue or gross profit for lifetime value?
Gross profit. Acquisition cost is a real cash cost, so pairing it with a revenue figure compares two numbers measured on different bases. On a 25 percent margin that error overstates the ratio fourfold, which is more than enough to reverse the decision it informs.
Is a ratio of 8:1 better than 3:1?
Usually not. A very high ratio means customers are worth far more than they cost to acquire, which is an argument for acquiring many more of them. Sustained over time it generally signals a marketing budget that is too small rather than a business that is unusually efficient.
What does a ratio below 1:1 mean?
Every new customer costs more than they will ever contribute, so growth actively destroys value and scaling makes the position worse. The fix is retention, pricing, or margin rather than more spending, and until one of those moves, additional acquisition budget accelerates the loss.
How does payback period relate to this ratio?
The ratio measures whether acquisition is worth it eventually, payback measures how long the money is tied up before it comes back. A strong ratio with a long payback can still exhaust a business that has to fund the gap, which is why the two are read together rather than separately.
Numbers are the easy part
Getting the calculation right takes two inputs. Getting an organization to agree on what counts as gain, what counts as cost, and what the number should change takes considerably longer.
That translation work is most of what I do. Westphal Solutions builds websites, tools, and reporting for nonprofits and growing teams, including the kind of measurement setup that makes a number like this one worth trusting in the first place.
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