SaaS LTV Calculator: 3 Formulas + Examples (2026)

A SaaS LTV calculator estimates how much gross profit one customer will produce before they churn. The practical default is: monthly ARPA × gross margin ÷ monthly customer churn rate.

If your monthly ARPA is $100, gross margin is 80%, and monthly customer churn is 4%, estimated LTV is $2,000. That number is useful, but only if the inputs use the same time period and describe the same customer segment.

Quick SaaS LTV calculator

Use these three inputs: monthly ARPA, gross margin, and monthly customer churn. Convert percentages to decimals before calculating. For example, 80% becomes 0.80 and 4% becomes 0.04.

Formula: SaaS LTV = Monthly ARPA × Gross Margin ÷ Monthly Customer Churn Rate

Example: $100 × 0.80 ÷ 0.04 = $2,000 LTV.

This result says an average customer is expected to contribute about $2,000 in gross profit over the relationship. It does not say the customer will pay $2,000 in a straight line, and it does not account for discounting, expansion, contraction, or major changes in churn.

What each input means

Monthly ARPA

Average revenue per account, or ARPA, is subscription MRR divided by active paying accounts. Use accounts rather than seats when the account is the economic buyer. If you have $50,000 in MRR from 500 active accounts, monthly ARPA is $100.

Gross margin

Gross margin is revenue minus the direct cost of serving customers, divided by revenue. SaaS cost of goods sold can include hosting, third-party infrastructure, payment processing, and customer support that is directly tied to delivery. Use the same accounting definition every month.

Monthly customer churn

Customer churn is the number of customers lost during the month divided by customers active at the start of the month. Exclude customers acquired during the month from the starting base. If you began with 500 customers and lost 20, monthly customer churn is 4%.

Three SaaS LTV formulas and when to use them

1. Revenue LTV for a fast directional estimate

Formula: Revenue LTV = Monthly ARPA ÷ Monthly Customer Churn Rate.

With $100 ARPA and 4% churn, revenue LTV is $2,500. This is fast and easy, but it treats every dollar of revenue as value. Use it for a rough revenue forecast, not for deciding how much you can profitably spend to acquire a customer.

2. Margin-adjusted LTV for unit economics

Formula: Margin-adjusted LTV = Monthly ARPA × Gross Margin ÷ Monthly Customer Churn Rate.

With $100 ARPA, 80% gross margin, and 4% churn, margin-adjusted LTV is $2,000. This is the best default for comparing LTV with customer acquisition cost because it removes the direct cost of serving the customer.

The same customer produces $2,500 in estimated lifetime revenue but only $2,000 in estimated lifetime gross profit. Confusing those figures can make an acquisition channel look healthier than it is.

3. Cohort LTV for expansion, contraction, and uneven churn

Formula: Cohort LTV = Sum of monthly gross profit per original customer across the observed cohort lifetime, plus a conservative estimate for the unobserved tail.

Suppose a January cohort starts with 100 customers. Its gross profit per original customer is $72 in month one, $70 in month two, $67 in month three, and so on. Add the monthly values over time instead of forcing a constant churn assumption.

Cohort LTV is the better choice when upgrades, downgrades, annual plans, usage-based charges, or early-life churn materially change customer value. It also exposes whether a small number of high-value accounts are hiding weak retention in the average.

A worked example with three customer segments

Imagine a SaaS company with Starter, Growth, and Enterprise plans. Starter has $40 ARPA, 85% gross margin, and 6% monthly churn. Growth has $150 ARPA, 82% gross margin, and 3% churn. Enterprise has $1,500 ARPA, 75% gross margin, and 1% churn.

Starter LTV: $40 × 0.85 ÷ 0.06 = $567. Growth LTV: $150 × 0.82 ÷ 0.03 = $4,100. Enterprise LTV: $1,500 × 0.75 ÷ 0.01 = $112,500.

The blended average would be nearly useless for acquisition decisions. You should compare Starter CAC with Starter LTV, Growth CAC with Growth LTV, and Enterprise CAC with Enterprise LTV. Segment by plan, acquisition channel, geography, or sales motion whenever those groups behave differently.

Be cautious with the Enterprise estimate. A 1% churn rate creates an expected lifetime of 100 months, so a tiny measurement error produces a large swing. Long contracts and small customer counts make cohort analysis more reliable than a simple inverse-churn formula.

How to build the calculation in a spreadsheet

Create columns for segment, MRR, active customers, customers at the start of the month, customers lost, gross margin, ARPA, churn, revenue LTV, and margin-adjusted LTV.

Use ARPA = MRR / active customers. Use churn = customers lost / customers at the start of the month. Use margin-adjusted LTV = ARPA × gross margin / churn. Format margin and churn as percentages, but confirm the underlying values are decimals.

Add at least six monthly rows per segment before treating the output as a planning input. A trailing average reduces the damage from one unusual month. Never mix annual churn with monthly ARPA; convert both to the same period first.

Five mistakes that make SaaS LTV misleading

1. Using revenue churn in a customer-churn formula. Revenue churn and logo churn answer different questions. Use customer churn with ARPA unless you deliberately choose a revenue-retention model.

2. Ignoring gross margin. Revenue LTV overstates what you can spend on acquisition because hosting and delivery costs still exist.

3. Combining incompatible periods. Monthly ARPA divided by annual churn produces nonsense. Align the units before calculating.

4. Trusting a tiny denominator. When churn approaches zero, calculated LTV explodes. Use longer observation windows and cohort evidence before budgeting against the result.

5. Hiding segments inside one average. Self-serve, sales-assisted, and enterprise customers often have different ARPA, margin, churn, and CAC. A blended LTV can approve the wrong channel and starve the right one.

How to use LTV without fooling yourself

Compare LTV with fully loaded CAC from the same segment and acquisition period. The familiar 3:1 LTV-to-CAC ratio is a planning heuristic, not a law. Cash flow, payback time, sales capacity, and confidence in the LTV estimate still matter.

Use LTV to set acquisition guardrails, prioritize retention work, compare customer segments, and test pricing changes. Do not use it as a vanity metric. If no decision changes when LTV changes, the metric is doing no job.

Track the inputs beside the output. A rising LTV caused by lower churn is strategically different from a rising LTV caused by higher prices or improved gross margin. Your dashboard should make that cause visible.

Calculate SaaS LTV from your database without SQL

The spreadsheet method becomes fragile once subscription, invoice, customer, plan, and cancellation data live in separate tables. AI for Database lets you connect the source database and ask for the calculation in plain English without exporting recurring CSV files.

A useful prompt is: “Calculate monthly ARPA, logo churn, gross margin, margin-adjusted LTV, CAC, and LTV:CAC by plan for the last 12 months. Exclude test accounts and show the formula used for each metric.” Review the table joins and definitions before trusting the result.

Save the result as a self-refreshing dashboard, then add an alert when LTV falls by more than 10% or LTV:CAC drops below your operating threshold. That turns LTV from a quarterly spreadsheet exercise into a metric your team can monitor and act on.

Start with read-only database access and validate a few accounts manually. Once the definitions match finance and billing, use the dashboard for recurring decisions. You can try this workflow at https://app.aifordatabase.com.

Questions founders ask about SaaS LTV calculators

What is the simplest SaaS LTV formula?

Use monthly ARPA × gross margin ÷ monthly customer churn. It is a practical starting point for a stable subscription business with enough churn history.

Should SaaS LTV use revenue or gross profit?

Use gross profit when comparing LTV with CAC or making acquisition decisions. Revenue LTV is acceptable for a quick top-line estimate, but it overstates the economic value of a customer.

Can I calculate LTV when churn is zero?

Not reliably with the inverse-churn formula. Zero observed churn usually means the window is too short or the customer count is too small. Use cohort cash flows, a longer observation period, and a conservative forecast.

How often should a SaaS company update LTV?

Update the inputs monthly and review segment-level LTV on a rolling basis. Recalculate immediately after a major pricing, packaging, cost, or acquisition-channel change.

What tool can calculate SaaS LTV from a live database?

Use a database analytics tool that can join billing, subscription, customer, and cost data, document the formula, and refresh the result automatically. AI for Database supports plain-English analysis, live dashboards, and threshold-based workflows in one product.

Method references

The margin-adjusted formula and its limitations are documented by ChartMogul at https://chartmogul.com/saas-metrics/ltv/ and Paddle at https://www.paddle.com/resources/cac-ltv-ratio. Stripe explains the inverse-churn model and SaaS unit economics at https://stripe.com/guides/atlas/business-of-saas.