SaaS Metrics Calculator
Calculate LTV, CAC payback, LTV:CAC ratio, ARR, and net revenue retention for your subscription business.
Inputs
Key Metrics
ARR
$600,000
Annual Recurring Revenue
LTV
$5,000
Lifetime Value
LTV:CAC Ratio
10.0x
Healthy
CAC Payback
3.3 mo
Efficient
Net Revenue Retention
97.0%
Revenue declining
MRR Projection (36 months, no new customers)
Shows the compounding impact of churn on your existing revenue base.
How it works
SaaS metrics measure the health of a subscription business. LTV (Lifetime Value) tells you how much a customer is worth over their entire relationship. CAC (Customer Acquisition Cost) tells you how much it costs to get one. The ratio between them — LTV:CAC — is the single most important metric for SaaS sustainability. Anything above 3:1 means your unit economics work.
The formula
Why it matters for your business
SaaS businesses live or die by unit economics. If it costs you $500 to acquire a customer who's only worth $400 over their lifetime, you'll burn cash faster the more you grow. These metrics tell you whether to invest in acquisition (LTV:CAC is strong) or retention (churn is killing LTV).
Pro tip
The most underrated SaaS metric is CAC Payback Period. Even with a great LTV:CAC ratio, if it takes 18+ months to recoup acquisition costs, you need significant cash reserves to fund growth. If your payback exceeds your runway, you have a timing problem — not a business model problem.
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