You spent EUR 50 to acquire a customer. Is that good or bad?
You cannot answer that question without knowing Customer Lifetime Value (LTV) -- the total revenue you can expect from a single customer over their entire relationship with your product. If that customer's LTV is EUR 500, spending EUR 50 to acquire them is an incredible deal. If their LTV is EUR 40, you are losing money on every sale.
LTV is the metric that turns guesswork into strategy. It tells you how much you can spend on marketing, when to invest in retention, and whether your pricing is sustainable. Here is how to calculate it, use it, and grow it.
The LTV Formula
The simplest version of the LTV formula uses two numbers you should already be tracking:
LTV = ARPU / Monthly Churn Rate
Where:
- ARPU = Average Revenue Per User (monthly)
- Monthly Churn Rate = Percentage of customers who cancel each month (as a decimal)
A Worked Example
Say you run a SaaS with these numbers:
- 80 paying customers
- EUR 3,200 MRR
- 4 customers churned last month
Your ARPU = EUR 3,200 / 80 = EUR 40/month Your monthly churn rate = 4 / 80 = 5% (0.05) Your LTV = EUR 40 / 0.05 = EUR 800
This means the average customer will pay you EUR 800 over their lifetime. Knowing this changes every decision you make.
The Inverse: Average Customer Lifetime
If your monthly churn rate is 5%, your average customer lifetime is:
Average Lifetime = 1 / Churn Rate = 1 / 0.05 = 20 months
So the average customer sticks around for 20 months, paying EUR 40/month, for a total of EUR 800. The math checks out.
For more on calculating churn rate correctly, check our MRR, ARR, and churn guide.
The LTV:CAC Ratio
LTV on its own is useful, but it gets powerful when you compare it to your Customer Acquisition Cost (CAC) -- how much you spend to acquire each customer.
CAC = Total acquisition spending / Number of new customers
If you spent EUR 1,000 on marketing last month and got 20 new customers, your CAC is EUR 50.
The LTV:CAC ratio tells you whether your growth is profitable:
| LTV:CAC Ratio | What It Means | |---|---| | Below 1:1 | You are losing money on every customer. Stop spending. | | 1:1 to 2:1 | Barely breaking even after accounting for costs. Tighten spend. | | 3:1 | The sweet spot. EUR 3 of lifetime value for every EUR 1 spent. | | 5:1 or above | You are under-investing in growth. Spend more to grow faster. |
Most SaaS benchmarks target a 3:1 LTV:CAC ratio as the minimum for healthy, sustainable growth.
A Practical Example
Using the numbers from above:
- LTV = EUR 800
- CAC = EUR 50
- LTV:CAC = 16:1
That is an extremely healthy ratio. It means you could spend significantly more on acquisition -- up to EUR 267 per customer (to maintain a 3:1 ratio) -- and still be profitable. If you are not investing in growth with those numbers, you are leaving revenue on the table.
Once you know your LTV, decisions that used to feel like gut calls become obvious. For example, if your LTV is EUR 800 and you are debating whether to sponsor a newsletter for EUR 200 per placement, the question is not "Can I afford it?" -- it is "Will this bring in at least one customer?" That reframing changes everything. LTV turns marketing from a cost center into a math problem with a clear answer.
Why LTV Matters for Indie Hackers
You might be thinking "I do not spend on marketing, so CAC does not apply to me." But CAC is not just ad spend. It includes:
- Your time writing blog posts, doing cold outreach, posting on social media
- Tools you pay for (email marketing, analytics, landing page builders)
- Partnerships or sponsorships you invest in
- Content creation costs (design, video, etc.)
If you spend 20 hours a month on marketing and your time is worth EUR 50/hour, your monthly marketing "spend" is EUR 1,000. If that brings in 10 customers, your CAC is EUR 100.
LTV also helps you decide:
- Which channels to invest in. If customers from Twitter have a EUR 600 LTV but customers from Product Hunt have a EUR 200 LTV, focus on Twitter even if Product Hunt drives more signups.
- Whether to offer a free tier. Free users cost you money (server, support). If your free-to-paid conversion rate is 2% and paid LTV is EUR 800, each free user is worth EUR 16 in expected value. Can you serve them for less than that?
- When to raise prices. If your LTV:CAC is above 5:1, you have room to increase prices. Even if some customers churn, the higher ARPU will likely increase overall LTV. See our pricing strategy guide for how to do this.
How to Increase LTV
There are exactly three ways to increase LTV, and each one is worth pursuing:
1. Reduce Churn
This is the highest-leverage move. Reducing monthly churn from 5% to 3% does not sound dramatic, but watch what it does to LTV:
- At 5% churn: LTV = EUR 40 / 0.05 = EUR 800
- At 3% churn: LTV = EUR 40 / 0.03 = EUR 1,333
A 2-percentage-point improvement in churn increased LTV by 67%. That is why every SaaS metric article tells you to focus on retention. The math is staggering.
Practical ways to reduce churn:
- Fix your onboarding. Most churn happens in the first 30 days. If customers do not reach their "aha moment" quickly, they leave. Identify what that moment is and build a path to it.
- Send engagement emails. A simple "You have not logged in for 7 days" email recovers surprisingly many at-risk customers.
- Ask churned customers why. Add a one-question survey to your cancellation flow. The patterns will tell you exactly what to fix.
- Implement dunning management. 20-40% of churn is involuntary (failed credit cards). Automated retry + card update emails recover a meaningful chunk.
2. Increase ARPU
Higher revenue per customer directly increases LTV.
- Add a higher-priced tier. If your top plan is EUR 29/month and power users would pay EUR 79/month, you are leaving money on the table. The tier does not need many subscribers to meaningfully increase your average.
- Offer annual billing. Annual plans often carry a slight premium (or at minimum reduce churn because customers prepaid). Even a 17% "discount" on annual billing improves LTV because annual customers churn at roughly half the rate of monthly ones.
- Usage-based add-ons. Let customers pay for what they use beyond the plan limits. Extra seats, extra projects, extra API calls. This creates natural expansion revenue.
You can model how ARPU changes affect your LTV and revenue with the SaaS Calculator.
3. Add Expansion Revenue
Expansion revenue is additional revenue from existing customers through upgrades, add-ons, and cross-sells.
The best SaaS businesses have negative net revenue churn -- meaning expansion revenue from existing customers exceeds revenue lost from cancellations. When that happens, your customer base grows even without new signups.
Practical expansion tactics:
- Design plans that customers outgrow. Set limits that active users hit naturally (subscriber count, project count, API calls). When they hit the limit, the upgrade is obvious.
- Launch new features on higher tiers. Releasing a premium feature gives existing customers a reason to upgrade without you having to sell them.
- Offer done-for-you services. Some customers will pay for setup, migration, or custom configuration. This adds one-time revenue that boosts effective LTV.
One underrated tactic: send a personal email to every customer who hits their 90-day mark. Thank them, ask what they would change, and mention the next tier up. It costs nothing, reduces churn by catching frustrations early, and plants the upgrade seed at exactly the moment the customer has proven they find value. A simple automated email at the right time can do more for LTV than a month of feature work.
LTV by Cohort: The Advanced Move
Simple LTV (ARPU / churn) treats all customers the same. But in reality, customers acquired in different months or from different channels behave differently.
Cohort-based LTV groups customers by when they signed up and tracks their revenue over time:
| Cohort | Month 1 | Month 3 | Month 6 | Month 12 | Projected LTV | |---|---|---|---|---|---| | Jan 2026 | EUR 40 | EUR 38 | EUR 35 | EUR 32 | EUR 720 | | Feb 2026 | EUR 42 | EUR 41 | EUR 40 | -- | EUR 950 | | Mar 2026 | EUR 45 | EUR 44 | -- | -- | EUR 1,100 |
In this example, newer cohorts have higher ARPU and lower churn, suggesting product improvements are working. If you saw the opposite trend, it would signal a problem with newer customer quality or onboarding.
You do not need fancy analytics for this. A simple spreadsheet tracking monthly revenue per signup cohort gives you enough data after 3-4 months.
Common LTV Mistakes
Using Annual Churn Instead of Monthly
If your annual churn is 40%, your monthly churn is not 40/12 = 3.3%. The correct conversion is:
Monthly churn = 1 - (1 - annual churn)^(1/12) Monthly churn = 1 - (1 - 0.40)^(1/12) = 4.2%
The difference seems small, but it meaningfully affects your LTV calculation.
Ignoring Variable Costs
LTV tells you gross revenue per customer, not profit. If each customer costs you EUR 5/month in hosting, support, and payment processing, your net LTV is lower:
Net LTV = (ARPU - variable cost per customer) / churn rate Net LTV = (EUR 40 - EUR 5) / 0.05 = EUR 700
Use net LTV when making acquisition spending decisions. Use gross LTV for benchmarking.
Calculating LTV Too Early
You need at least 3 months of data for a meaningful churn rate, which means your LTV calculation is unreliable until you have been charging customers for at least a quarter. Before that, focus on retention qualitatively -- talk to customers, watch for usage patterns, and build engagement.
Putting It All Together
Here is a practical LTV dashboard for any indie SaaS:
- ARPU: Check monthly. Is it growing? (More on this in our MRR guide)
- Monthly churn rate: Check monthly. Is it stable or declining?
- LTV: Recalculate quarterly. Is the trend up?
- LTV:CAC ratio: Recalculate quarterly. Above 3:1?
- Expansion revenue: Are existing customers paying more over time?
If ARPU is rising, churn is falling, and LTV is growing, your business is getting healthier even if top-line growth seems slow. These are the metrics that compound.
Calculate your LTV instantly with the SaaS Calculator or track it automatically with IndieBase