#927 · Startup Tool

Seed Stage LTV Calculator

Estimate customer lifetime value, customer lifetime, and LTV:CAC ratio for seed-stage SaaS. Use it to evaluate unit economics before scaling sales and marketing.

Calculator

Seed-stage inputs
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How to use this calculator

  • Enter monthly ARPA per account.
  • Enter gross margin as a percentage.
  • Enter monthly churn and CAC to calculate lifetime value and unit economics.

What the result means

LTV estimates gross profit over a customer lifetime. LTV:CAC compares that value with acquisition cost. Strong ratios require retention, margin, and efficient acquisition.

Customer Lifetime = 1 / Monthly Churn Rate. LTV = ARPA × Gross Margin × Customer Lifetime. LTV:CAC = LTV / CAC.

Early-stage LTV can be unstable when churn cohorts are small. Recalculate by cohort as data improves.

Example calculation

If ARPA is $250, margin is 80%, churn is 4%, and CAC is $750, lifetime is 25 months, LTV is $5,000, and LTV:CAC is 6.67x.

Tips for better results

  • Use cohort churn rather than blended churn when possible.
  • Improve retention before scaling acquisition.
  • Increase ARPA through packaging and expansion.
  • Compare LTV:CAC with CAC payback.

FAQ

How do I calculate LTV for a seed-stage SaaS startup?

Multiply monthly ARPA by gross margin and expected customer lifetime. Customer lifetime is often approximated as one divided by monthly churn rate.

What is a good LTV:CAC ratio for SaaS?

A ratio around 3:1 is often considered healthy, while ratios above 5:1 can indicate strong unit economics if data quality is reliable.

Why is my LTV:CAC ratio too low?

Low retention, low ARPA, weak gross margin, or high CAC can all reduce LTV:CAC. Fixing retention usually has the largest impact.

Should seed startups trust early LTV calculations?

Early LTV should be treated as directional because churn cohorts may be small and customer behavior can change quickly.

How does reducing churn increase SaaS LTV?

Lower churn increases expected customer lifetime, which raises LTV even when ARPA and margin stay the same.

Seed-stage decision table

MetricMeaning
LTVEstimated gross profit over customer lifetime.
Customer LifetimeExpected months retained.
LTV:CACValue created for each acquisition dollar.
Unit EconomicsHealth of customer profitability.

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