{
  "id": 18494756,
  "title": "SaaS Metrics for Developers: MRR, Churn, LTV:CAC and Runway, With the Math in Code",
  "url": "https://urgent.news/2026/11/06/saas-metrics-for-developers-mrr-churn-ltv-cac-and-runway-with-the",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-11-06T12:05:00.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/startupreader/saas-metrics-for-developers-mrr-churn-ltvcac-and-runway-with-the-math-in-code-leg"
  },
  "original_language": "en",
  "account": "1. MRR (Monthly Recurring Revenue) normalizes all recurring revenue to a monthly basis. It is calculated by taking the price of each plan, converting annual plans to monthly, and summing them up. Revenue from setup fees, free trials, unpaid pilots, one-off services, and taxes should be excluded. The formula is mrr = subs.reduce((sum, s) => sum + monthly(s), 0). Alternatively, ARR (Annual Recurring Revenue) can be calculated by multiplying MRR by 12.\n\n2. Net new MRR represents the change in MRR due to new subscriptions, upgrades, and cancellations. It can be broken down into four components: newMRR (new subscriptions), expansion (customer upgrades), contraction (customer downgrades), and churned (canceled subscriptions). The formula is netNew = newMRR + expansion - contraction - churned. Net revenue retention (NRR) is the percentage of revenue retained from existing customers, calculated as (start + expansion - contraction - churned) / start * 100.\n\n3. Churn describes the percentage of customers who leave in a given period. It compounds over time, and it's important to distinguish between customer churn (customers lost) and revenue churn (revenue lost). To calculate churn, divide the number of customers lost by the number of customers at the start of the period. The formula for annual churn is (1 - (1 - monthly) ^ 12) * 100, and the average customer lifetime can be calculated as 1 / monthly.",
  "summary": "Your side project has paying users. Stripe shows a balance, a chart that mostly goes up, and a list of payments. Then someone asks for your MRR, your churn or your LTV:CAC, and the dashboard doesn't quite answer. Most of these metrics are a line or two of arithmetic. What makes them confusing is the definitions: what counts as recurring, which churn, revenue or profit. Get those wrong and the…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}