MRR & ARR Calculator
Multiply paying customers by average revenue per account to get monthly recurring revenue, annualize it to ARR, and see whether expansion revenue is outrunning churned MRR.
Reviewed by the CalcCafe editorial team · Last updated 18 July 2026 · How we test our tools
Example
Suppose you have 500 paying customers at an average of $99 per month. MRR = 500 × 99 = $49,500, and ARR = 49,500 × 12 = $594,000. If existing customers add $2,000 of expansion MRR this month but you lose $3,000 to churn and downgrades, net MRR movement is -$1,000 — the base is shrinking even before new sales — and the NRR proxy is (49,500 + 2,000 − 3,000) ÷ 49,500 ≈ 98.0%, just below the 100% line where a SaaS business retains its revenue without any new logos.
How it works
MRR = paying customers × average revenue per account per month, counting only revenue that recurs under subscription. ARR = MRR × 12 — a snapshot annualization, not a forecast. Net MRR movement = expansion MRR − churned MRR (new-logo MRR is deliberately excluded so you can see the health of the existing base). The NRR proxy = (starting MRR + expansion − churn) ÷ starting MRR × 100, which approximates net revenue retention over one month; true NRR is measured on a cohort over a full year. All figures return 0 rather than an error when inputs are empty.
Good to know
MRR normalization is where most reported numbers go wrong. Only contractually recurring subscription revenue belongs in MRR: monthly plan fees, and annual or multi-year contracts divided by their term in months. One-time setup fees, implementation and services revenue, non-recurring usage spikes and marketplace transaction fees are all excluded — investors will strip them out during diligence, and a company that books services into ARR can see 20-30% of its headline number evaporate on the first data-room pass. If usage-based revenue is a core, repeatable part of the model, disclose it as a separate line rather than silently blending it in.
ARR is MRR times twelve, and that is all it is: a run-rate snapshot, not a promise of next year's revenue. Distinguish it from trailing-twelve-month revenue (backward-looking, includes non-recurring items) and from a run-rate built off a single spiky month. Also distinguish committed ARR (CARR) — signed contracts including those not yet live or billed — from billed or live ARR. Late-stage investors increasingly ask for both, because a large CARR-to-ARR gap can signal slow implementations or contracts that never activate.
Net revenue retention is the single multiple-driving metric hiding in this calculator. NRR of 100% means the existing base replaces its own churn with expansion; 110%+ is the commonly cited good benchmark for B2B SaaS, and the elite public performers (Snowflake, Datadog in their high-growth years) printed 130%+. Below 100%, every new dollar of bookings first has to refill a leaking bucket — at 90% NRR a $10M ARR business must sell $1M of new ARR each year just to stand still. The one-month proxy here compounds: 98% monthly retention is roughly 78% annualized, which is a very different business than the monthly number suggests.
Watch the interaction between net MRR movement and growth reporting. A company can report growing MRR while net movement on the existing base is negative, because new-logo sales mask base churn — that pattern caps out the moment sales efficiency dips. Best practice is a full MRR bridge each month: starting MRR + new + expansion − contraction − churn = ending MRR. The bridge makes gross retention (churn and contraction only) visible alongside net retention, and gross retention below roughly 85-90% annually is a red flag for most B2B investors regardless of how strong expansion looks.
Frequently asked questions
What counts as MRR and what should I exclude?
Include only contractually recurring subscription revenue: monthly plan fees and annual contracts divided by 12. Exclude one-time setup fees, professional services, non-recurring usage overages and transaction fees. Investors strip non-recurring revenue out during diligence, so it is better to normalize your MRR honestly from the start.
Is ARR just MRR times 12?
Yes — ARR here is an annualized run-rate snapshot of current MRR, not a revenue forecast. It differs from trailing-twelve-month revenue, which looks backward and can include non-recurring items, and from committed ARR, which counts signed contracts that may not yet be live or billed.
What is a good net revenue retention (NRR) benchmark?
100% means expansion exactly offsets churn in the existing base. For B2B SaaS, 110%+ is generally considered good and 130%+ is elite, territory occupied by the best public infrastructure companies. Consumer and SMB products often run below 100% because of naturally higher churn.
Is my data uploaded anywhere?
No — this calculator runs entirely in your browser. Your customer counts and revenue figures never leave your device, and the page keeps working offline once loaded. It is completely free with no sign-up.
People also ask
How do I calculate MRR from annual contracts?
Divide the annual contract value by 12 and add that to MRR for each month the contract is active. A $12,000 annual deal contributes $1,000 of MRR — never book the full amount into a single month's MRR.
What is the difference between committed ARR and billed ARR?
Committed ARR (CARR) counts all signed recurring contracts, including customers not yet onboarded or billed. Billed or live ARR counts only revenue actually being invoiced. A persistent gap between the two can signal slow implementations or contracts that never go live.
Why is my MRR growing while net MRR movement is negative?
New-logo sales are masking churn in your existing base. New MRR is excluded from net movement precisely to expose this: if expansion minus churn is negative, the installed base is shrinking and growth stalls as soon as new sales slow down.
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Sources & references
These tools follow our methodology and provide educational estimates only — verify important figures with a qualified professional.