SaaS Metrics Calculator

Essential SaaS subscription metrics

Software-as-a-service companies track recurring revenue and retention to understand growth quality. Monthly recurring revenue (MRR) captures subscription inflows each month, while annual recurring revenue (ARR) annualizes the ending MRR base. Net revenue retention (NRR) shows whether existing customers expand, contract, or churn.

This calculator turns customer counts, ARPU, and expansion or contraction dollars into MRR, ARR, net new MRR, customer churn, and NRR for a single period. To estimate long-run customer economics, combine results with the SaaS LTV calculator. For acquisition efficiency, review the CPA calculator.

MRR and ARR formulas

Starting MRR equals starting customers multiplied by ARPU. Net new MRR adds new and expansion revenue and subtracts contraction and churned MRR:

Ending MRR is starting MRR plus net new MRR. ARR is ending MRR times 12: $\mathrm{ARR} = \mathrm{Ending\ MRR} \times 12$. Customer churn rate for the period is churned customers divided by starting customers.

Net revenue retention (NRR)

NRR measures revenue retained from the starting cohort, including expansion and contraction, before new logo revenue:

NRR above 100% means existing customers grew revenue net of churn. Best-in-class B2B SaaS companies often report NRR above 110%. Customer-level retention is related but distinct; see the customer retention rate calculator for logo retention.

Worked example

Start with 100 customers at $250 ARPU, add 15 customers, lose 3, and record $500 expansion MRR and $200 contraction MRR.

1. Starting MRR: $100 \times 250 = 25{,}000$.
2. New MRR: $15 \times 250 = 3{,}750$. Churned MRR: $3 \times 250 = 750$.
3. Net new MRR: $3{,}750 + 500 - 200 - 750 = 3{,}300$. Ending MRR: $28{,}300$.
4. ARR: $28{,}300 \times 12 = 339{,}600$. NRR: $(25{,}000 + 500 - 200 - 750) / 25{,}000 = 98.2\%$.

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