Free SaaS Metrics Calculator

A customer lifetime value (LTV) calculator designed for SaaS businesses enables you to project the net profit a single subscriber contributes throughout the entire relationship. By entering a handful of essential metrics, you can obtain a reliable LTV figure and use it to guide pricing, retention strategies, and growth investments. This article walks through each parameter, explains the underlying formula, and demonstrates a typical calculation.

Key Parameters for LTV Estimation

When you use this tool in its basic mode, you supply the following inputs:

• ARPA (Average Revenue Per Account) – also called average revenue per user (ARPU). It represents the monthly revenue earned from one subscription account.
• Gross Margin – the percentage of revenue retained as profit after direct costs. For example, a 20% gross margin means you keep $0.20 from every dollar. The default is 100% (no costs). The calculation is $$\text{Gross Margin} = \frac{\text{Revenue} - \text{Costs}}{\text{Revenue}}.$$
• Churn Rate – the fraction of customers who cancel each month. If you lose 3 out of 100 subscribers in a month, your churn rate is 3%. Monitoring this metric is vital for reducing attrition.
• Account Expansion – the expected monthly increase in ARPA per customer. Setting a value like $10 means each customer pays an extra$10 each month (first month $100, second$110, third $120, and so on).
• LTV – the average net profit generated from a customer account over its active lifetime. The calculator computes this automatically once the other fields are filled.

If you don’t know your ARPA directly, select the “I don’t know the ARPA” option and provide:

• Number of Customers – the total count of active subscribers.
• MRR (Monthly Recurring Revenue) – the sum of all monthly subscription payments across every customer.

The tool then divides MRR by the number of customers to obtain ARPA.

Customer Lifetime Value Formula

The calculator uses the following equation to determine LTV:

$$\text{LTV} = \left[ 0.5 \times \frac{1}{\text{Churn}} \times \left( 2 \times \text{ARPA} + \text{ARPA\_growth} \times \left( \frac{1}{\text{Churn}} - 1 \right) \right) \right] \times \text{Margin}$$

Where:

• $\text{Churn}$ is the monthly churn rate (expressed as a decimal, e.g., 0.04 for 4%).
• $\text{ARPA\_growth}$ is the monthly account expansion amount.
• $\text{Margin}$ is the gross margin (e.g., 0.65 for 65%).

All inputs must be in consistent monthly units for the result to be accurate.

Example Calculation

Consider a SaaS company with 25 customers and an MRR of $6,000. The ARPA is therefore$6,000 ÷ 25 = $250. Assume the gross margin is 65$0.

Plugging these numbers into the formula:

$$\begin{aligned} \text{LTV} &= \left[ 0.5 \times \frac{1}{0.04} \times \left( 2 \times 250 + 0 \times \left( \frac{1}{0.04} - 1 \right) \right) \right] \times 0.65 \\ &= \left[ 0.5 \times 25 \times (500 + 0) \right] \times 0.65 \\ &= \left[ 12.5 \times 500 \right] \times 0.65 \\ &= 6,\!250 \times 0.65 \\ &= \$4,\!062.50 \end{aligned}$$

This means each customer is expected to contribute an average net profit of $4,062.50 over their entire relationship with the service. By adjusting any of the inputs—such as improving churn or increasing account expansion—you can see how those changes affect LTV and prioritize the most impactful actions.