Every SaaS story has the same scene: it’s the first week of the month, a founder or agency owner is hunched over Google Sheets and Excel, hunting for updated customer counts, copying Stripe exports, and trying to remember which column is churn and which is expansion.
An MRR calculator cuts through that chaos. By standardizing the formula (MRR = average revenue per account × active customers) and centralizing inputs, you get a single source of truth for growth, churn, and forecasts. It turns scattered invoices and CRM notes into a simple, comparable metric you can use in board meetings, sales standups, and marketing planning. Like the machining MRR examples, you define a clear formula and feed in the right dimensions: plan price, customer count, new, churned, expanded.
But the real leverage comes when an AI computer agent takes over the drudgery. Instead of you logging into billing tools, downloading CSVs, and massaging columns, the agent can open Google Sheets or Excel, pull the latest numbers from your browser or desktop apps, apply the MRR formulas, and refresh charts on a schedule. You stay focused on why the numbers are moving; the agent handles how they get calculated.
If you run a subscription business, your Monthly Recurring Revenue is the heartbeat of your company. Let’s walk through practical ways to build an MRR calculator—from fully manual to fully automated with an AI agent—so you can stop scrambling at month-end.
Month, Active Customers, ARPA, MRR.ARPA (Average Revenue Per Account), enter your subscription price (e.g., $49).Active Customers, enter the customer count for each month.MRR cell, use the formula:=B2*C2 (assuming B is customers, C is ARPA).Docs: Google Sheets formulas guide — https://support.google.com/docs/answer/3093480
Plan, Price, Customers.Total MRR cell, use:=SUMPRODUCT(B2:B5, C2:C5) (B = prices, C = customers).Churned Customers by plan and compute Churned MRR using another SUMPRODUCT.New MRR, Churned MRR, Net New MRR, Total MRR.
Insert > Table).Status column with a formula to check if the customer was active in a given month (e.g., using IF with start/cancel dates).Price for active customers by month. This gives you MRR by month directly from transactional data.Docs: Excel formulas overview — https://support.microsoft.com/en-us/office/create-a-formula-in-excel-ecfdc708-9162-49e8-b993-c311f47ca173
Customer ID, Plan, MRR, Status, Created At, Cancelled At to columns.SUMIFS, FILTER) to compute:New MRR (customers created this month).Churned MRR (customers cancelled this month).Expansion MRR (upgrades).Docs: Connect forms to Sheets — https://support.google.com/docs/answer/2917686
Data > Get Data).Docs: Excel data import basics — https://support.microsoft.com/en-us/office/import-and-analyze-data-66bf7ee6-2eaf-4d10-9d52-5b53b83bb8a6
Now imagine an AI agent that uses your computer like a smart assistant—opening the browser, logging into billing tools, exporting reports, and updating Sheets or Excel for you.
Story: Each month, instead of your ops lead doing the “MRR dance,” your Simular AI agent does it.
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When you combine solid spreadsheet models with an AI agent that can click, type, and calculate on your behalf, MRR moves from a painful monthly ritual to a continuous, reliable signal for every decision you make.