LTV/CAC Ratio

How to Perform Cohort Analysis Using LTV to CAC Ratio

The majority of companies examine LTV/CAC at a more granular level using a customer cohort analysis, which rather than looking at just a single “average customer,” breaks down customers into multiple different customer groups according to various parameters such as demographics or even the initial year of acquisition.

After performing cohort analysis using the LTV:CAC ratio, a couple examples of insightful questions that can be answered include the following:

• Q. Based on historical profitability and product demand, which customer profile should the company target?
• Q. Is the current state of the business model feasible in terms of becoming profitable someday in the future while being able to scale efficiently?
• Q. How much spending should be allocated toward hiring sales reps and marketing campaigns?

Upon calculating the LTV/CAC for each customer profile, the most profitable customers must be determined and then be strategically marketed towards.

Companies can oftentimes benefit from narrowing their market focus and establishing a niche based on their most profitable segments (and later have the option to enter other markets).

As a side benefit, a targeted sales & marketing campaign permits more effective, personalized marketing since the specific end markets and customer types are identified.

Otherwise, the company might eventually continue burning cash at an unsustainable rate until it is ultimately forced to unwind and shut down operations.

For early-stage SaaS companies moving beyond the product development period, being able to monetize users consistently, maintaining high customer retention rates, and the efficient allocation of capital are critical components in obtaining market traction and continuing to grow.

The underlying components that contribute the LTV/CAC ratio are as follows.

• Customer Lifetime Value (LTV) → 1) Retention Rate, 2) Gross Margin and 3) ARPA
• Customer Acquisition Cost (CAC) → 1) Marketing Efficiency and 2) Sales Efficiency

The reason LTV/CAC carries such importance is that each dollar spent to acquire new customers should be justified by the value derived from those customers in return.

LTV/CAC Ratio Calculator | Excel Template

We’ll now move on to a modeling exercise, which you can access by filling out the form below.

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1. Lifetime Value (LTV) Calculation Example

The lifetime of the customer represents the implied duration an average customer remains with the company.

Since we are working towards estimating the value of a customer, we must take into account how long a typical customer does business with a company, as no customer stays a customer perpetually.

As we mentioned earlier, certain customers will ultimately unsubscribe (in the case of a subscription-based company) or otherwise stop purchasing at some point. We call this the customer churn rate, which is defined as the percentage of existing customers who discontinue their relationship with the company in a given year.

The formula used to calculate the customer lifetime is thus one divided by the customer churn rate.

For example, if the annual customer churn rate is 5% (which means that 5% of existing customers discontinue their relationship with the company in any given year), then the lifetime would be calculated as 1 ÷ 5%, which comes out to 20 years. We can interpret 20 years as being the average length an average customer stays a customer of the company.

The flip side of thinking about the churn rate is the retention rate. The retention rate is the average percentage of customers who continue their relationship with the company in any given year, and is calculated as 1 minus the churn rate. In our example here, the retention rate would thus equal 95%.

• Retention Rate = 1 – 5% = 95%.

Although our example used an annual churn rate, a monthly churn rate could also be used here. But regardless of which is used, the important thing is to remain consistent throughout the entirety of the calculation with either monthly or annual metrics in order to avoid timing mismatches.

2. ARPA Calculation Example

Once we know how long on average a given customer stays a customer with the company, to continue in our calculation of LTV, we need to know how much revenue on average a given customer generates per year.

To estimate the average revenue generated by a single given customer per year, we calculate the average revenue per account (“ARPA”).

The formula for ARPA is the company’s total recurring revenue divided by the current number of active users.

As previously mentioned, be mindful of being consistent regarding timing. Since we used the annual churn above, we will now use annual recurring revenue (“ARR”) as the numerator in the ARPA formula.

Once ARPA is calculated, it is multiplied by the gross margin to arrive at the gross contribution per customer.

Note that to calculate gross contribution per customer, we should only take into account the variable costs directly related to serving the customer.

And then, LTV can be calculated using the formula below:

To reiterate, the LTV denotes the average gross contribution a single customer is expected to generate for the business over its lifetime.

The LTV is critical to track because it can be among the most useful data points in projecting the future revenue that can be expected from each customer.

As such, LTV can be a proxy for the “value” of the customer to the company. And by quantifying how much value the average customer provides during the entire lifespan of their relationship, the company can measure how much it can reasonably spend to acquire these customers.

3. Margin Multiple Calculation Example (LTV Discount Rate)

The inclusion of a discount rate as part of the LTV formula accounts for the time value of money and reflects how much a company values receiving payment right now versus at a later date.

The standard discount rates range around:

• Public Companies → 8% to 10%
• Late-Stage Private Companies → 10% to 15%
• Early-Stage Start-Ups → 15% to 20%+

Discount rates are higher for an early-stage company because it values earlier payments more given its risk profile (i.e., cash burn rate, urgent spending needs, inconsistent free cash flows).

However, the discount rates used are highly subjective and will vary depending on the person performing the analysis. Certain people use a 10% discount rate for early-stage, high-risk companies under the assumption that the company would someday be public (i.e., a best-case scenario).

The margin multiple is the right side of the LTV formula shown above. Often referred to as the “multiplier”, it is calculated with the retention rate as the numerator, and the denominator consisting of one plus the discount rate minus the retention rate.

Here, the gross profit contribution by the customer is taken and multiplied by the present value of the lifetime – thus, the output could be interpreted as a “discounted” customer lifetime value.

In the hypothetical scenario used in our template, the key financial data is as follows:

• ARPA → The ARR is $2.5mm with 10,000 total customers, which means ARPA is $250
• Gross Contribution → Upon applying the 80% gross margin to the ARPA, the gross contribution per customer comes out to $200
• Retention Rate → Given the 5% annual churn rate, the retention rate can be backed out of by just subtracting the churn rate from one, which is 95%
• Margin Multiple → To calculate the margin multiple, the 95% retention rate is the numerator, while the denominator is comprised of 1 plus the 10% discount rate, less the 95% retention rate
• Lifetime Value → The LTV can now be calculated by multiplying the $200 gross contribution by the margin multiple of 6.3x, which comes out to approximately $1.27k

4. Customer Acquisition Cost (CAC) Calculation Example

The customer lifetime value (LTV) is a proxy for how profitable acquired customers acquired are, which is compared to the spending required to acquire them.

Now the LTV has been calculated, we can move on to calculating the customer acquisition cost (CAC), the denominator in the LTV/CAC ratio.

CAC is the total cost incurred to make the customer initially purchase the products being sold. In short, the CAC is the sum of all sales & marketing (“S&M”) expenses divided by the total number of new users acquired.

To acquire new customers, companies use a variety of marketing tactics, sales channels (e.g., digital, social media), and in-person strategies – furthermore, the effectiveness and return on investment of those strategies can be measured via the LTV/CAC ratio.

Going back to our example, the three channels (and cash outflows) related to new customers acquisitions are:

1. Sales Team Compensation → Ten sales reps that are each paid $65k every year
2. Digital Marketing Campaign Expenses → $20k is spent on digital marketing such as targeted social media and email campaigns
3. Search Engine Marketing Expenses → SEM utilizes a pay-per-click (“PPC”) model, where one click costs $1.00 and there were a total of 10,000 site visits (and therefore a $10k expense)

From the prior section, we determined that our hypothetical company spent $680k to acquire 1.6k new customers this year, which comes out to a CAC of $425.

• Total Sales and Marketing Spend = $680k
• New Customer Additions = 1.6k
• Customer Acquisition Cost (CAC) = $425

5. LTV/CAC Ratio Calculation Example

So we’ve now arrived out our final step, where we have computed the two components required to calculate the LTV/CAC ratio.

The only remaining step here is to divide the two parts that we calculated up to the current point.

The completed output from our model is shown below, which shows our company’s LTV/CAC ratio comes out to 3.0x.

• LTV/CAC Ratio = $1.27k ÷ $425 = 3.0x

By dividing the LTV of $1.27k by the CAC of $425, we arrive at 3.0x for the implied LTV/CAC. Another way to think about this result is that for every $1 spent on sales and marketing, the company generated $3 of additional gross contribution.

6. Alternative LTV to CAC Calculation Example

An alternative approach uses a simpler formula for calculating the lifetime value (LTV), also eliminating the concept of a discount rate:

Based on our completed LTV/CAC ratio model, we can derive the following takeaways:

• Step 1 → The ARR is $100,000 with 2,000 customers (and $50 average revenue per account, or ARPA), meaning this is a seed-stage company (sub-$1mm revenue)
• Step 2 → By dividing the contribution margin of $43 ($50 ARPA x 85% Gross Margin) by the annual churn rate of 10%, we get an LTV of $425
• Step 3 → In the last step, we can divide the $425 LTV by the $417 CAC (50k S&M Spend ÷ 120 New Customers), which comes out to an implied LTV/CAC a slight bit over 1.0x
• Step 4 → For each dollar spent on sales and marketing, the company generated only $1.00 of additional gross contribution. Basically, it is only just breaking even on its sales and marketing spend.