LTV to CAC Ratio Calculator

Sure, you might go out and blow a bunch of cash on marketing. But what happens when that customer leaves after they’ve spent less than their worth? In that case, the business model doesn’t hold up. In this case, you’re not operating a viable business. You’re throwing money at your marketing team and nothing more.

For all its investor-related uses, LTV/CAC represent an indicator of unit economics… Does this business work? Once you plug in your revenue, margin, and churn numbers into the calculator, it do all that math for you.

How to Use This Tool to Check Your Business

It forces you to use gross profit instead of revenue. A lot of entrepreneurs only care about their top line sales number which is where they get all fuzzy. That’s why you need to think in terms of gross profit rather than revenue. The cash you actualy keep is what pays back the acquisition cost. You’re overvaluing the worth of every customer if you don’t account for server, fulfillment, or support costs.

The other key input is monthly churn. This sounds obvious but gets screwed up here and it blows the whole thing. Over 3 years, a percent point shift in retention move your LTV by hundreds of dollars. There are two ways the tool lets you do this. One is a simple net churn formula. But the other, a cohort projection, is more strict. You see how customers realy leave. This limits the value to a specific time window and prevents you from counting revenue that might not occur.

Second, it’s about expansion revenue: Does the customer purchase additional products in the future? That extra spend contributes to the value of the customer. Even if it’s small and positive, it can offset some acquisition cost. This is the big difference here; you can plug in expansion into the calculator separately. Many simple calculators assumes no expansion, but real companies either grow with their customers or they downgrade. Knowing the actual expansion rates allows for a conservative vs. This allows for a realistic estimate.

Look carefully at the payback period in the output. Three-to-one isn’t bad, but if you’ll only break even after thirty months, then you could be out of money before that happens. More startups die from cash-flow issues than they do from long-term unit economics issues. How do you know? Well, the reference table tells you.

Two-to-one works well for fast-payback ecommerce. But it’s too aggressive for long-cycle B2B software. What’s reasonable depends on context.

The second number, the ratio… Also deserve careful monitoring. A ratio greater than five to one could indicate that you’re not investing enough for growth. As long as it remains profitable to acquire new customers, you can afford to spend more. This tool will calculate the max acquisition cost at which you should stop based on your desired ratio. So think of that as a guardrail.

Are your real-world costs significantly lower than that? Consider increasing spend or trying different customer-acquisition channels. What it tells you is where the problems lie. Is the ad cost too high? -> Is the ad cost too high? You can’t improve what you don’t measure, and you can’t scale a losing business.

Try varying inputs to see what works. For example, if you make your product more efficient, you can increase margins. Try dropping the churn by half a percent to see how it affects the ratio. Observe how this impacts the ratio.

Discipline is essential. Understand exactly what it costs you to acquire a customer. Understand exactly how much that customer pays back in the long run. Intuition won’t get you there; the math will.

Keep a healthy ratio and monitor the payback period to prepare for continued expansion. Don’t expect instant returns. Expect long-term financial security.