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Free customer lifetime value to acquisition cost (LTV:CAC) calculator

See your customer acquisition cost (CAC) payback period: how long a customer takes to pay back what it cost to win them. Plus what each one is worth in gross profit (lifetime value, LTV), and how much you can afford to spend to get the next one.

Cost
100% free
For
Subscriptions (SaaS) and repeat purchase
Email
Not needed

Your numbers · prefilled with starting guesses

How customers pay

Cost to win a customer (CAC)

$

Ads, tools, agencies and salaries.

In the same period.

$/ month
%

Monthly customer churn.

%

Revenue minus cost to deliver.

Your unit economics

Each customer costs $3,000 to win

Payback period

8.0 months

12
target16
median36+0

Lifetime value to CAC (LTV:CAC)

4.2:1

Healthy

Lifetime value

$12,500

Gross profit over 33 months.

Verdict

Inside the commonly cited 3:1 to 5:1 range: each customer pays back what it cost with room to spare.

What you can afford to spend per customer

At a 3:1 LTV:CAC ratio
$4,167
To pay back in 12 months
$4,500

You spend $3,000. That's $1,167 below the tighter limit: room to spend more on growth.

What improves it most

  1. 01Cut monthly churn by a fifth5.2:1 · 8.0 months
  2. 02Cut acquisition cost by 10%4.6:1 · 7.2 months
  3. 03Raise price by 10%4.6:1 · 7.3 months
  4. 04Raise gross margin by 5 points4.4:1 · 7.5 months

Payback = customer acquisition cost (CAC) ÷ (monthly revenue per customer × gross margin). Lifetime value (LTV) is gross profit, not revenue: using revenue overstates it. Lifetime = 1 ÷ monthly churn. Targets: 3:1 and under 12 months are David Skok's widely used software-as-a-service (SaaS) benchmarks; the 16-month median payback is Benchmarkit's 2025 SaaS data (198 companies; middle half 10–24 months). Both are guides, not rules for every business.

How it works

How the LTV:CAC & CAC Payback Calculator works

  1. 01

    Pick how customers pay

    Subscription (monthly revenue and churn) or repeat purchase (order value, orders a year and years retained).

  2. 02

    Add your acquisition cost

    Sales and marketing spend and new customers won in the same period, or your customer acquisition cost (CAC) if you know it. Include salaries, tools and agencies.

  3. 03

    Add your gross margin

    Revenue minus the cost to deliver, as a percentage. Without it, payback and LTV look better than they are.

  4. 04

    Read your unit economics

    Payback period in months against the 12-month target and 16-month median, the lifetime value to CAC (LTV:CAC) ratio with a verdict, and lifetime value in gross profit.

  5. 05

    See what you can afford

    The most you can spend per customer at 3:1 and for a 12-month payback, and which lever improves the numbers most.

Built and maintained by Swapan Kumar Manna, go-to-market and AI search strategist. Updated .

Questions

Questions about the LTV:CAC & CAC Payback Calculator

What it does, what it costs, and how far to trust the result.

01How do I calculate customer acquisition cost (CAC) payback?

CAC payback (months) = CAC ÷ (monthly revenue per customer × gross margin). For example, a $560 CAC on a $50-a-month customer at 80% gross margin pays back in 560 ÷ 40 = 14 months.

02What is a good lifetime value to customer acquisition cost (LTV:CAC) ratio?

About 3:1 is the widely used target, from David Skok's SaaS Metrics. Below 1:1 you lose money on each customer; between 1:1 and 3:1 the margin is thin; above 5:1 you may be under-investing in growth.

03What is a good CAC payback period?

Under 12 months is the common target. In Benchmarkit's 2025 SaaS data (198 companies) the median was 16 months, with the middle half between 10 and 24 months. Longer payback needs more cash to fund growth.

04Should lifetime value (LTV) use revenue or gross profit?

Gross profit. Revenue-based LTV ignores what it costs to deliver the product, so it overstates what a customer is worth and how much you can afford to spend to win one.

05Does it work for ecommerce and repeat-purchase businesses?

Yes. Choose repeat purchase and enter average order value, orders per customer a year and years a customer stays. For example, $65 orders three times a year for 2.5 years at 55% margin is about $268 of gross profit, so a 3:1 ratio allows up to about $89 to win each customer.

06Is the LTV:CAC calculator free?

Yes, completely free, with no sign-up and no email. It runs in your browser and nothing you enter is sent anywhere.

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