Monthly recurring revenue (MRR)

What counts, and what does not

The arithmetic is the sum of every active subscription, each expressed as a monthly amount. A customer on a $1,200 annual plan contributes $100 of MRR in each of the twelve months, including the eleven when no money arrives. A customer on a $99 plan holding a 20% discount contributes $79.20, because MRR counts what they actually pay and not the list price. A customer inside a free trial contributes nothing at all until the trial converts.

The exclusions are where most founders end up with a number that does not mean what they think. One-time setup and onboarding fees are not recurring; neither are professional-services engagements, hardware, or taxes you collect and pass on. Discretionary usage — the overage a customer might or might not incur next month — is genuinely unpredictable, so folding it in turns a run rate into a guess. Committed minimums are the exception: a customer contractually obliged to spend a floor every month is recurring revenue whatever the contract calls it.

MRR movement is the number that tells you something

MRR as a single figure tells you the size of the business. What it can do for you only appears once you break down how it changed, because four different things move it and they carry opposite news:

• New MRR — from customers who were not paying last month. This is the acquisition engine, and the only component that requires strangers.
• Expansion MRR — existing customers paying more than they did: an upgrade, extra seats, a higher tier. The cheapest revenue in the business, because the trust was already earned.
• Contraction MRR — existing customers paying less without leaving. The easiest one to miss, because the logo is still on the wall and the customer count has not moved.
• Churned MRR — lost because a customer left entirely. The component that quietly sets a ceiling on everything above it.

Net new MRR is new plus expansion minus contraction minus churn. Two companies can report the same MRR and the same growth rate while being in genuinely different businesses: one growing on new customers with heavy churn underneath, the other barely acquiring but expanding inside a base that stays. When expansion exceeds contraction and churn combined, the base grows on its own — net revenue retention above 100%, sometimes called negative churn. See churn rate for the other side of that arithmetic and customer lifetime value for what the retention is worth.

MRR vs ARR, and where MRR misleads

Annual recurring revenue is MRR multiplied by twelve. The arithmetic is trivial; the honesty is not. ARR fairly describes a business selling annual contracts, and becomes a projection dressed as a fact when the base is month-to-month and a third of it could be gone by December. Quote whichever one your contracts actually are — and when someone quotes ARR at you, the question worth asking is what their average contract length is.

MRR also stays silent about three things that matter. It says nothing about cash timing: an annual prepay is the full amount in the bank today and one twelfth of it in this month's MRR, which is how a business can be growing MRR while running out of money, or shrinking it while flush. It says nothing about margin, so revenue costing you 80% to deliver looks identical to revenue costing you 10%. And it flatters any business that lets one-time revenue leak in, which is exactly why the exclusions above are worth being strict about.

First-party note from building AgentCeres — the AI Growth Officer at agentceres.com: our own revenue does not fit into one number, and that turned out to be the useful thing about it. A subscription plan is billed monthly, and on top of it the language-model usage a customer's agents actually consume is billed through at cost plus a small markup — so part of what arrives each month is a subscription and part of it moves with how much work got done. Read as one total, it looked like growth. Split apart, the two halves answer different questions: the recurring part tracks how many people decided we are worth keeping, the variable part tracks how much they gave us to do. A heavy usage month would have read as new customers if we had blended them, and we would have celebrated the wrong thing. If any of your revenue is variable, the discipline that pays is settling the definition before you want the chart to go up. Pirate metrics is where a revenue number belongs in the wider funnel.