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Tool · Startups

SaaS metrics calculator

The unit economics investors ask about, from a few numbers you already track.

Customer lifetime value (LTV)
$4,000
LTV to CAC
4.00x
CAC payback
12.5 months
Annual recurring revenue (ARR)
$600,000
Revenue per customer per month
$100.00
Average customer lifetime
50 months
Net new MRR
$5,000

LTV = revenue per customer × gross margin ÷ monthly churn. A simple model: it assumes constant churn and pricing.

How it’s calculated

Revenue per customer is MRR divided by customers. Average customer lifetime is 1 divided by monthly churn. Lifetime value (LTV) is revenue per customer times gross margin times that lifetime.

CAC payback is the months of gross profit from one customer needed to repay what it cost to acquire them. Net new MRR is new MRR minus churned MRR. ARR is MRR times 12.

Worked example

$50,000 MRR from 500 customers is $100 each. With 2% monthly churn (a 50-month lifetime) and 80% gross margin, LTV is $4,000. At a $1,000 acquisition cost, LTV to CAC is 4x and payback takes 12.5 months.