SaaS LTV Calculator: Calculate Customer Lifetime Value Step by Step

Understanding your LTV is arguably the most critical component of measuring your software company's long-term viability. Without a clear picture of what a customer is worth over their lifetime, you cannot accurately forecast revenue, determine how much to spend on marketing, or evaluate the overall health of your subscription model.

While many founders rely on a SaaS LTV calculator to do the heavy lifting, knowing exactly how this metric is derived step-by-step ensures you can diagnose growth bottlenecks and make strategic, data-backed decisions.

The Core SaaS LTV Formulas

Depending on the maturity of your business and the depth of your financial data, there are a few ways to calculate Customer Lifetime Value. The most universally accepted formula for SaaS factors in gross margin to give you a true picture of profitability, rather than just top-line revenue.

How to Calculate Customer Lifetime Value: Step by Step

Step 1: Determine Average Revenue Per User (ARPU)

Your ARPU represents the average monthly recurring revenue you receive from a single customer. To find this, simply divide your Total MRR by your total number of active customers.

Example: If your MRR is $50,000 and you have 500 customers, your ARPU is $100.

Step 2: Calculate Your Gross Margin

Not every dollar of revenue is profit. Gross margin deducts the Cost of Goods Sold (COGS) from your revenue. For SaaS, COGS typically includes server costs, software hosting fees, and customer support infrastructure.

Example: If your COGS is 20% of your revenue, your Gross Margin is 80% (or 0.80).

Step 3: Measure Your Customer Churn Rate

Churn rate is the percentage of customers who cancel their subscription in a given month. Identifying and learning how to reduce churn is essential because even slight improvements drastically increase LTV.

Example: If you start the month with 500 customers and 25 cancel, your monthly churn rate is 5% (or 0.05).

Step 4: Put It All Together

Now, apply these variables to the True SaaS LTV formula:

Metric	Value
ARPU	$100
Gross Margin	80% (0.80)
Customer Churn Rate	5% (0.05)
Calculated LTV	($100 x 0.80) / 0.05 = $1,600

Why LTV Doesn't Exist in a Vacuum

Knowing that a customer is worth $1,600 is only helpful if you know how much it costs to acquire them. This relationship forms your unit economics foundation. A standard SaaS benchmark is keeping a healthy LTV to CAC ratio of 3:1.

Additionally, modern SaaS companies should look beyond just replacing churned customers. Fostering expansion revenue (upsells and cross-sells) increases your Net Revenue Retention, which actively drives up your LTV over time without acquiring a single new user.