SaaS subscription growth metrics.

MRR (Monthly Recurring Revenue) calculator tracks SaaS subscription business growth. Net New MRR = New MRR + Expansion MRR - Churned MRR. Growth rate = Net New / Previous MRR × 100. Healthy SaaS companies target 10-15% monthly MRR growth at early stage, 5-10% at scale.

Example: previous MRR 50,000, new 8,000, expansion 2,000, churned 3,000. Net new = 7,000. Current MRR 57,000. Growth rate 14%. ARR (Annualised Run Rate) = 684,000. Investors heavily focus on MRR growth, churn rate, and net revenue retention - the three core SaaS metrics.

MRR variants: New MRR (new customers), Expansion MRR (upgrades from existing customers), Contraction MRR (downgrades), Reactivation MRR (returning customers), Churned MRR (cancellations). Net New MRR is the headline metric. SaaS Magic Number = Net New ARR / Sales+Marketing spend - measures efficiency of growth investment.

A worked example

Try the defaults: previous period mrr of 50,000, new mrr of 8,000, expansion mrr of 2,000, churned mrr of 3,000. The tool returns 14.00%. You can adjust any input and the result updates as you type — no submit button, no reload. That's the real power here: seeing how sensitive the output is to one or two assumptions.

What moves the number most

The result responds to Previous Period MRR, New MRR (new customers), Expansion MRR (upgrades), and Churned MRR (cancellations). Not every input has equal weight. Flip one at a time toward extreme values to feel which ones move the needle most for your situation.

The formula behind this

Current MRR = previous + new + expansion - churned. Growth % = net new / previous × 100. ARR = current × 12. Everything the calculator does is shown in the formula box below, so you can check the math against your own spreadsheet if you want.

What to do with a low result

A disappointing result is information, not a judgement. Pick the single input that dragged the figure down most and focus the next quarter on that one factor. Breadth-first improvement rarely works; depth-first on the worst input usually does.

What this doesn't capture

The score is a composite of the inputs you provide. Life context — job security, family obligations, health, housing — doesn't appear in the math but shapes the real picture. Use the number as a prompt, not a verdict.