The five numbers investors ask about first, defined precisely so your board deck holds up under scrutiny.
The SaaS Metrics Glossary: MRR, Churn, LTV, CAC & NRR Defined
A precise glossary of core SaaS metrics — MRR, churn, LTV, CAC, NRR — with the 2026 healthy-range benchmarks founders should know.
Every SaaS board deck leans on the same five metrics. Precision matters here — vague definitions make numbers incomparable across companies. Here's how each is actually calculated, with 2026 benchmark context.
The core five
MRR (Monthly Recurring Revenue) — Normalized, predictable subscription income generated each month, explicitly excluding one-time fees, professional services revenue, and other non-recurring charges.
Churn (revenue churn / MRR churn) — The percentage of recurring revenue lost in a period due to cancellations or downgrades, separate from logo (customer-count) churn.
CAC (Customer Acquisition Cost) — Total sales and marketing spend divided by the number of new customers acquired in a period.
LTV (Lifetime Value) — The total gross margin a customer generates over their relationship with the company, used against CAC to judge unit economics.
NRR (Net Revenue Retention) — Calculated as (Starting MRR + Expansion − Contraction − Churn) ÷ Starting MRR × 100; measures revenue growth or decay from the existing customer base alone, excluding new logos.
Reading the numbers — 2026 benchmarks
LTV:CAC ratio — Above 3:1 is generally considered healthy; below 1:1 means the company loses money on every customer acquired.
CAC payback period — How many months of gross margin it takes to recoup acquisition cost; the 2026 market median is roughly 15-18 months, with elite companies achieving under 12.
Gross margin — Healthy SaaS businesses typically run 70-85% gross margins.
NRR benchmark — Above 100% means expansion revenue is outpacing churn and contraction; top performers in 2026 are hitting 120%+.
Revenue growth — Median annual SaaS revenue growth has cooled to roughly 26% in 2026, down from 47% in 2024, reflecting a broader market slowdown.
Sources
Beancount: The 2026 SaaS Metrics Stack, Eagle Rock CFO: SaaS Benchmarks by Stage 2026.
Frequently asked questions
MRR (Monthly Recurring Revenue) is the normalized monthly subscription income; ARR (Annual Recurring Revenue) is simply MRR multiplied by 12 — both exclude one-time or non-recurring charges.
NRR shows whether your existing customer base is growing or shrinking in value on its own — a business with NRR above 100% can grow purely from expansion revenue even with zero new customers.
It means a company loses money on every customer it acquires over that customer's lifetime — a ratio of exactly 1:1 is break-even, and healthy SaaS businesses target above 3:1.