Calculate your NRR from MRR components, compare against benchmarks, and see the waterfall. Free, instant, no signup.
NRR = (Starting + Expansion − Contraction − Churned) / Starting × 100
What the number doesn't tell you
This tool tells you what the data says. The 23-point buyer-side churn audit checklist tells you what to request, in what order, and which answers are red flags — the list to work through before you sign an LOI.
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Get the full buyer-side checklist that PE analysts use to assess retention quality before a deal.
Get the full buyer-side due diligence checklist →This free net revenue retention calculator tool gives you a quick, no-signup assessment based on the inputs you provide. The methodology behind it is the same one ChurnLens uses in full buyer-side due diligence, just applied to summary inputs rather than a complete revenue ledger. The output is directional — it tells you whether the numbers you have suggest a healthy business or one with structural churn risk — and it is designed to be conservative, erring on the side of flagging potential problems.
The limitation of any summary-input tool is that it cannot detect the patterns that only emerge from customer-level data: zombie accounts, cohort decay curves, concentration in specific logos, and renewal-cliff timing. Those require the full monthly MRR-by-customer ledger that ChurnLens's paid analysis ingests. Use this free tool as a first-pass screen; if it flags anything concerning, the next step is to send the full ledger for the complete reconstruction.
The formulas and benchmarks used here are transparent and documented across the ChurnLens learn hub. There is no black box — the goal is to give you the same arithmetic a buyer's diligence team would run, in a format you can use immediately.