How to Calculate LTV for SaaS (Formula, Examples, Common Mistakes)

Most bootstrapped SaaS founders know they should calculate LTV. Few actually do it. And of those who do, most get it wrong in ways that silently distort every growth decision they make.

Here is the problem: LTV is not just a number you calculate once and forget. It is the foundation of your unit economics. It tells you how much you can afford to spend acquiring a customer, whether your pricing is working, and whether your business model is sustainable. Get it wrong, and you will either overspend on acquisition or underprice your product for years.

This post will give you the formula, walk through it with real numbers, and then show you the three mistakes that make most LTV calculations misleading.

The formula

There is one formula. It is simple.

LTV = ARPU / Monthly Churn Rate

That is it. ARPU is your Average Revenue Per User per month. Monthly churn rate is the percentage of customers who cancel each month, expressed as a decimal.

If your ARPU is $50 and your monthly churn rate is 5%, your LTV is:

$50 / 0.05 = $1,000

This means the average customer will pay you $1,000 over their lifetime before they churn.

Calculate your LTV right now with our free calculator.

A worked example

Let us walk through a real scenario.

You run a project management tool for freelancers. You have 200 paying customers. Here are your numbers:

Monthly revenue: $8,000
Customers: 200
Customers lost last month: 8

Step 1: Calculate ARPU.

ARPU = $8,000 / 200 = $40/month

Step 2: Calculate monthly churn rate.

Churn Rate = 8 / 200 = 0.04 (4%)

Step 3: Calculate LTV.

LTV = $40 / 0.04 = $1,000

Your average customer is worth $1,000 over their lifetime. Now you know how much you can afford to spend to acquire one.

Why LTV matters more than revenue

Revenue tells you how much money came in this month. LTV tells you whether the money will keep coming.

Consider two SaaS companies:

| Metric | Company A | Company B | |--------|-----------|-----------| | MRR | $10,000 | $10,000 | | ARPU | $100 | $50 | | Monthly Churn | 10% | 2% | | LTV | $1,000 | $2,500 |

Same revenue. But Company B's customers are worth 2.5x more because they stick around longer. Company B can afford to spend more on acquisition, invest more in product, and grow more sustainably.

This is why tracking churn separately from other metrics matters so much. A small difference in churn creates a massive difference in LTV.

The LTV:CAC ratio

LTV alone is not enough. You need to compare it to what it costs you to acquire a customer.

LTV:CAC Ratio = LTV / CAC

Below 1:1 means you are losing money on every customer. Urgent problem.
1:1 to 3:1 means you are breaking even or slightly profitable. Tight, but workable.
3:1 to 5:1 is the healthy range. You have room to grow.
Above 5:1 means you are either very efficient or you are underinvesting in growth.

Here is the thing most founders miss: a very high LTV:CAC ratio is not always good news. If your ratio is 8:1 and you are growing at 2% per month, you are probably leaving money on the table. You could afford to spend more on acquisition and grow faster.

Use the Growth Machine to see where your users are flowing.

Gross-margin-adjusted LTV

The basic formula assumes every dollar of revenue is profit. It is not.

If you are paying for servers, third-party APIs, or support staff, your gross margin is less than 100%. A more accurate LTV accounts for this:

Gross-Margin-Adjusted LTV = (ARPU x Gross Margin) / Monthly Churn Rate

Example: Same $40 ARPU and 4% churn, but your gross margin is 80%.

LTV = ($40 x 0.80) / 0.04 = $800

Your real LTV is $800, not $1,000. That changes how much you can afford to spend on CAC.

For most bootstrapped SaaS companies with low infrastructure costs, gross margin is between 75% and 90%. If yours is below 70%, you have a cost problem worth investigating before worrying about acquisition.

The 3 mistakes that make LTV useless

Mistake 1: Using annual churn instead of monthly churn

This is the most common error. Annual churn and monthly churn compound differently.

5% monthly churn is not 60% annual churn. It is:

Annual churn = 1 - (1 - 0.05)^12 = 1 - 0.54 = 46%

If you plug 60% annual churn into the LTV formula, you get a different (wrong) number. Always use monthly churn in the formula.

The reverse mistake is also common: taking your annual churn, dividing by 12, and calling it monthly churn. 46% annual churn divided by 12 gives you 3.8%, not 5%. The error seems small but compounds into a significantly wrong LTV.

Mistake 2: Mixing up logo churn and revenue churn

Logo churn (also called customer churn) counts the number of customers who leave. Revenue churn (also called MRR churn) counts the dollars lost.

These can be very different. If your cheapest customers churn the most, logo churn will be higher than revenue churn. If your biggest customers churn, the opposite.

For LTV, use logo churn if you are calculating per-customer lifetime value. Use revenue churn if you are calculating per-dollar lifetime value. Do not mix them.

For bootstrapped SaaS with a single pricing tier, the difference is small. But if you have multiple plans, this distinction matters.

Mistake 3: Calculating LTV too early

LTV needs stable churn data. If you launched two months ago and have 30 customers, your churn rate is statistically meaningless. Three customers leaving in month one is a 10% churn rate, but it could just be three people who signed up by accident.

Rule of thumb: Do not trust your LTV calculation until you have at least 6 months of churn data and 100+ customers. Before that, track it but do not make major spending decisions based on it.

What should you do instead? Focus on the leading indicators: activation rate and bounce rate. These tell you whether new users are getting value, which predicts future retention, which predicts future LTV.

LTV and the Growth State Machine

If you are using the Growth Machine framework, LTV connects directly to several flows:

Flow #12 (HV Retention) is the primary driver of high LTV. Every month a high-value user stays, your LTV goes up.
Flow #2 (Bounce) destroys LTV because bounced users have near-zero lifetime value. They drag your average down.
Flow #6 (Upgrade) increases LTV by moving low-value users into higher engagement (and often higher-paying) tiers.
Flow #10 (HV Churn) is the LTV killer. Losing a high-value user has an outsized negative impact on your average LTV.

The insight: LTV is not one number for your whole user base. High-value users have dramatically higher LTV than low-value users. If you only track one aggregate LTV, you miss this.

What to do with your LTV number

Once you have calculated LTV, here is what to do with it:

1. Set your CAC budget. If your LTV is $1,000 and you want a 3:1 ratio, you can spend up to $333 to acquire a customer. This gives you a concrete number for ad spend, content marketing investment, or outreach tools.

2. Check payback period. How many months until you recover CAC? If your ARPU is $40 and your CAC is $333, payback takes about 8 months. For a bootstrapped founder, payback under 12 months is healthy. Above 12 months and you are financing acquisition out of pocket for over a year.

3. Compare segments. Calculate LTV separately for different customer segments (by plan, acquisition channel, or industry). You may discover that customers from organic search have 3x the LTV of customers from paid ads. That changes where you invest.

4. Track it monthly. LTV changes as your churn rate and ARPU change. A monthly check-in keeps you ahead of problems. Set up your monthly metrics routine if you have not already.

Quick reference

| Metric | Formula | Example | |--------|---------|---------| | LTV | ARPU / Monthly Churn Rate | $50 / 0.05 = $1,000 | | Gross-Margin LTV | (ARPU x GM%) / Monthly Churn Rate | ($50 x 0.80) / 0.05 = $800 | | LTV:CAC Ratio | LTV / CAC | $1,000 / $250 = 4:1 | | Payback Period | CAC / ARPU | $250 / $50 = 5 months |

Calculate yours now

You could do this math in a spreadsheet. Or you could enter your numbers into Saasly's free calculator and get LTV, LTV:CAC, payback period, and 20+ other metrics calculated automatically. No signup required.

If you want AI-powered recommendations on what to focus on based on your actual numbers, create a free account. It takes 5 minutes and it is free forever.

Frequently asked questions

What is LTV in SaaS?

LTV (Customer Lifetime Value) is the total revenue you can expect from a single customer over their entire relationship with your product. For SaaS, it is calculated as ARPU divided by monthly churn rate. A customer paying $50/month with 5% monthly churn has an LTV of $1,000.

How do you calculate LTV for a SaaS company?

The simplest formula is LTV = ARPU / Monthly Churn Rate. If your average revenue per user is $80/month and your monthly churn rate is 4%, your LTV is $80 / 0.04 = $2,000. For a more accurate number, multiply ARPU by your gross margin percentage before dividing.

What is a good LTV for a bootstrapped SaaS?

There is no universal "good" LTV number. What matters is the LTV:CAC ratio. Aim for at least 3:1, meaning your LTV should be at least 3 times your customer acquisition cost. Below 3:1, your unit economics may not be sustainable.

What is the difference between LTV and CLV?

LTV and CLV (Customer Lifetime Value) are the same thing. SaaS companies tend to use "LTV" while e-commerce and traditional businesses use "CLV." The formula and meaning are identical.