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Finance

SaaS Metrics

LTV, CAC, payback period & gross margin in one shot.

MRR movements (last month)
Customers & unit economics
Net Revenue Retention
100.5%
bench 100%+
Gross Revenue Retention
95.5%
bench 80%+
LTV : CAC
5.87 : 1
bench 3:1+
CAC payback
5.7 mo
bench < 12 mo
Logo churn
2.00%
bench < 5%/mo
Revenue churn
3.00%
MRR lost ÷ MRR start
Magic number
6.00
> 0.75 = scale; > 1 = aggressive
LTV
$2,640
MRR end
$115,500
Δ $15,500
Benchmark — SMB
  • LTV:CAC — your 5.87 vs target 3:1
  • Payback — your 6 mo vs target < 12 mo
  • NRR — your 100% vs target 100%
  • GRR — your 96% vs target 80%
AI explainer

Ask anything about your result

The math above is deterministic. AI explains what it means — it never recalculates the numbers.

About

LTV, CAC, payback period, and contribution margin — the four numbers every SaaS founder gets asked about. Plug in ARPU, gross margin, churn, and CAC to get all four at once.

How it works

  1. 01LTV = ARPU × gross margin% × (1 / churn%).
  2. 02LTV:CAC = LTV / CAC. Healthy SaaS targets ≥ 3:1.
  3. 03Payback = CAC / (ARPU × gross margin%). Target < 12 months for venture-scale.
  4. 04Customer lifetime = 1 / churn%, in months.

Examples

Healthy SMB SaaS

$99 ARPU, 80% GM, 3% monthly churn, $450 CAC. LTV ≈ $2,640. LTV:CAC = 5.9:1. Payback = 5.7 months. Strong unit economics.

Trouble signals

If payback creeps past 18 months OR LTV:CAC drops below 2:1, you're paying for growth from cash, not revenue. Investors will notice.

FAQ

Should I use logo churn or revenue churn?+
Revenue churn for LTV — it captures expansion and contraction. Logo churn for raw retention reporting.
Why include gross margin?+
LTV is the present value of future cash, not revenue. A 30% margin business has very different LTV from a 90% margin SaaS at the same ARPU.
What CAC should I use?+
Fully-loaded sales & marketing spend over a period, divided by new logos acquired in the same period. Don't cherry-pick — include the AE base salary.

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