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What Is the LTV:CAC Ratio? Formula, Benchmarks and Examples
The LTV:CAC ratio compares what a customer is worth with what it cost to win them. Learn the formula, a worked example and what a good ratio looks like.
The LTV:CAC ratio tells you how much lifetime value a customer brings in for every dollar you spent to acquire them. A SaaS team that knows its LTV to CAC can decide how hard to push on sales and marketing, and when to fix retention first. This guide covers the formula, a worked example, what counts as a good ratio, and the mistakes that make the number misleading.
What is the LTV:CAC ratio?
The LTV:CAC ratio compares customer lifetime value (LTV) with customer acquisition cost (CAC). It is calculated as LTV divided by CAC. A ratio of 3:1 means each customer is expected to generate three dollars of value for every dollar spent to win them. It is a core efficiency metric for subscription and SaaS businesses.
LTV is the total value you expect from one customer before they leave. CAC is what you spend on sales and marketing to win one new customer. Put together, the two numbers answer one question: is growth profitable, or are you buying customers for more than they will ever return?
You will also see it written as LTV/CAC ratio or simply "LTV to CAC". They all mean the same thing. If you only need the cost side, see our page on the customer acquisition cost KPI. This article is about how that cost relates to what customers are worth.
How to calculate the LTV:CAC ratio
The calculation has three steps: work out LTV, work out CAC, then divide.
LTV:CAC ratio = LTV ÷ CAC
LTV formula for the LTV:CAC ratio: revenue vs margin
The simple version uses average revenue per account (ARPA) and the customer churn rate:
LTV = ARPA ÷ customer churn rate
The margin-based version multiplies by gross margin first:
LTV = ARPA × gross margin % ÷ customer churn rate
Prefer the margin-based version. Revenue is not what you keep. Hosting, support and payment fees come out of every dollar, so a revenue-only LTV overstates what a customer is worth and flatters the ratio. The revenue-based formula is fine for a quick first look or when you do not yet know your margin, but label it clearly. For definitions of the inputs, see average revenue per account and churned MRR.
Keep the time unit consistent. If ARPA is monthly, the churn rate must be monthly too, and the result is lifetime value in total dollars. Mixing monthly revenue with annual churn is the most common arithmetic error.
CAC formula for the LTV:CAC ratio
CAC = (sales cost + marketing cost) ÷ new customers acquired in the period
Include salaries, commissions, tools, agency fees and ad spend, not just media spend. Divide by the number of genuinely new customers in the same period.
LTV:CAC ratio worked example (fictional numbers)
Imagine a SaaS company with these monthly figures:
- ARPA: $120 per month
- Gross margin: 75 percent
- Monthly customer churn: 3 percent
- Sales and marketing cost last month: $40,000
- New customers last month: 40
| Step | Calculation | Result |
|---|---|---|
| Gross profit per account per month | $120 × 75% | $90 |
| Margin-based LTV | $90 ÷ 0.03 | $3,000 |
| Revenue-based LTV | $120 ÷ 0.03 | $4,000 |
| CAC | $40,000 ÷ 40 | $1,000 |
| LTV:CAC ratio (margin-based) | $3,000 ÷ $1,000 | 3:1 |
| LTV:CAC ratio (revenue-based) | $4,000 ÷ $1,000 | 4:1 |
The revenue-based shortcut makes the same business look a full point healthier. That gap is exactly why the margin-based figure is the one to report.
What is a good LTV:CAC ratio?
A ratio of around 3:1 is the widely used rule of thumb for a healthy SaaS business. David Skok, a venture investor, wrote that the best SaaS businesses have an LTV to CAC ratio higher than 3, while calling this and his other benchmarks only guidelines with exceptions. You can read his reasoning in SaaS Metrics 2.0 on For Entrepreneurs.
Treat 3:1 as a starting point, not a pass mark. Margins, sales cycles, contract length and growth stage all change what is acceptable. A company with high gross margins and fast payback can run lower, and a business with long enterprise cycles may need more headroom.
What each LTV:CAC range usually means
| Ratio | What it usually means | What to do |
|---|---|---|
| Below 1:1 | You lose money on every customer you acquire. | Pause scaling. Find out whether CAC is too high, churn is too high or pricing is too low. |
| 1:1 to 3:1 | Customers pay back, but slowly or thinly. Common in young companies. | Fix retention and conversion before adding spend. Check CAC payback. |
| 3:1 to 5:1 | Generally healthy and sustainable. | Keep investing, and watch the trend and payback period. |
| Above 5:1 | Very efficient, but you may be underinvesting in growth. | Test more spend, new channels or new segments, as long as payback stays acceptable. |
A very high ratio is not automatically good news. If every dollar returns more than five, the market may be giving you room to grow faster than you are.
CAC payback period: the companion to the LTV:CAC ratio
LTV:CAC says how much you earn over a customer's whole life. It does not say how long that takes. The CAC payback period fills the gap:
CAC payback (months) = CAC ÷ (monthly ARPA × gross margin %)
In the example above, that is $1,000 ÷ $90, or about 11 months. A business can show a healthy 3:1 and still run short of cash if payback is long. Read the two metrics together: the ratio for efficiency, payback for cash. Skok's article also discusses recovering CAC within roughly 12 months as a guideline.
Common LTV:CAC ratio calculation mistakes
Most wrong ratios come from a handful of errors:
- Using revenue instead of gross margin. This inflates LTV, as the example showed.
- Mixing blended and paid CAC. Blended CAC includes customers who arrive through word of mouth, so it looks lower than what paid channels actually cost. Know which one you are quoting.
- Ignoring the time lag. A deal closed this month may come from spend three months ago, especially with long sales cycles. Compare spend with the customers it produced, not just the customers who happened to close.
- Trusting churn from a young base. With a few months of data, one cancellation swings the churn rate and LTV with it. Treat early numbers as estimates.
- Mixing segments. A cheap self-serve plan and an enterprise contract have different churn, ARPA and CAC. One blended ratio hides which one is carrying the other.
- Leaving out costs. Onboarding, sales salaries and tools belong in CAC.
How to improve your LTV:CAC ratio
You can raise the top of the fraction or lower the bottom.
Raise LTV
- Retention. Cutting churn lengthens customer lifetime. Even small reductions compound, because the churn rate sits in the denominator of the LTV formula.
- Expansion. Upsells, extra seats and add-ons raise ARPA from customers you already have.
- Pricing. Packaging and price changes lift ARPA. Test on new customers first and watch churn afterwards.
Lower CAC
- Channel mix. Shift budget from channels with high cost per customer to those with a low one.
- Conversion rates. Better lead qualification and follow-up mean more customers from the same spend. Track your sales conversion rate to see where leads drop off.
- Sales cycle. Shorter cycles cost less rep time per deal. Keep an eye on average sales cycle length.
Segment your LTV:CAC ratio by channel, plan and cohort
One company-wide ratio is a starting point. The useful insight comes from splitting it.
- By channel: which sources bring customers that stay and pay back?
- By plan or customer size: is the entry plan profitable on its own, or carried by larger accounts?
- By cohort: do customers who signed up this year retain as well as last year's?
Segmenting often shows that the average ratio is fine while one channel or plan quietly drags it down.
How to track the LTV:CAC ratio on a SaaS dashboard
A spreadsheet works until the inputs live in three systems. The ratio needs billing data, CRM data and spend data, and each updates at a different time.
In Plecto, you can bring these sources together on one dashboard:
- Billing: connect Stripe or Chargebee to import subscription and payment data. Check the Stripe integration guide first, since it is currently in beta.
- CRM: pull new customers and deals from a CRM such as HubSpot.
- Spend: marketing and sales cost often sits in a spreadsheet. Import it from Google Sheets or upload an Excel file to a manual data source.
Once the data is in, you build the ratio as a formula on top of it. Plecto also has an AI formula assistant to help write formulas. Then add MRR, churn and CAC next to it, show the dashboard on an office TV, and use conditional colors to flag when the ratio drops below your threshold.
Real-time Plecto dashboard for monitoring the LTV:CAC ratio, MRR and churn on one screen
For the wider set of metrics to put around it, see 10 SaaS KPIs you should focus on and our guide to recurring revenue.
Conclusion: use the LTV:CAC ratio to steer growth spend
The LTV:CAC ratio turns "are we growing efficiently?" into one number you can track. Calculate it on gross margin, read it alongside CAC payback, and split it by channel and plan before you act on it. To keep it current without rebuilding a spreadsheet every month, see how a SaaS dashboard pulls billing, CRM and spend data together.
Questions
LTV:CAC ratio FAQs
A good LTV to CAC ratio for a SaaS business is commonly cited as about 3:1 or higher, meaning each customer returns three times what it cost to acquire them. Treat it as a rule of thumb. Gross margin, payback period and growth stage all change what counts as healthy for your company.
Divide customer lifetime value by customer acquisition cost. LTV is average revenue per account times gross margin percentage, divided by the customer churn rate. CAC is sales and marketing cost divided by new customers in the same period. Use the same time unit, such as months, for every input.
Not always. A ratio well above 5:1 is efficient, but it can mean you are underinvesting in growth and leaving customers on the table. If payback is short and churn is stable, test more spend or new channels. The goal is a ratio that is healthy and still lets you grow.
LTV:CAC measures how much value a customer returns over their whole life compared with acquisition cost. CAC payback measures how many months it takes to earn back that cost from gross profit. The ratio shows efficiency, while payback shows cash timing. Healthy businesses watch both.
Use gross margin. Revenue ignores the cost of serving the customer, such as hosting, support and payment fees, so a revenue-based LTV overstates value and flatters your LTV to CAC ratio. Revenue-based figures are fine as a quick estimate if you label them clearly.
Review it monthly or quarterly, and look at the trend rather than a single reading. Churn and CAC both move slowly, so one noisy month can mislead. A live dashboard that updates as billing and spend data change makes it easy to spot a drift early.
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