Free tool

Free LTV calculator

Calculate customer lifetime value

Enter ARPU, gross margin, and monthly churn. You'll get LTV plus LTV:CAC and payback (if you provide CAC).

$
Average revenue per user per month.
%
Revenue minus COGS, as a percentage.
%
Customer (logo) churn per month.
$
Optional. Used for LTV:CAC and payback.
Lifetime value
$4,800
LTV:CAC = 6.0× · Payback = 8.3 months · Avg. lifetime = 50 months
LTV = (ARPU × gross margin) / monthly churn
Average customer lifetime = 1 / monthly churn (in months)
Payback (months) = CAC / (ARPU × gross margin)
See LTV by cohort, plan, and segment on your real data. atSpark calculates LTV automatically from Stripe + HubSpot + QuickBooks. Try atSpark
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What's a healthy LTV:CAC?

The classic SaaS benchmark is 3× or higher — meaning a customer is worth at least 3× what it costs to acquire them. Below 1× means you're losing money on every acquisition. Above 5× and you might be under-investing in growth.

This formula assumes steady-state churn. If your cohort retention is improving over time (most SaaS), this number is conservative. For more accurate LTV, use cohort-based LTV which atSpark calculates by default.

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What about payback period?

Payback is how long it takes for a single customer's contribution margin to recover the CAC. Best-in-class SaaS targets under 12 months. Over 24 months and you're capital-intensive — fine if you have the runway and the retention.

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Why this is the most predictive number

If you only got to track one SaaS metric, it would be cohort retention — and LTV is essentially cohort retention multiplied by economics. A business with great LTV is a business with patient capital and a happy install base.

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