SaaS metrics
MRR, ARR, CAC, LTV, NRR, GRR, churn, runway, magic number, rule of 40 — every SaaS metric as a verified formula you can drop in and own.
20 pages · 3 reference, 15 how-to, 2 error fix
Reference
RANDARRAY
Spills a grid of random numbers with specified rows, columns, min, max, and integer/decimal options. Excel 365 and Google Sheets only.
ARRAYTOTEXT
Converts an array or range into a single text string, with concise or strict formatting options.
MAKEARRAY
Creates an array of specified dimensions by applying a LAMBDA function to generate each cell value.
How-to guides
How to calculate churn rate
Calculate monthly or annual customer churn rate as lost customers divided by starting customers, expressed as a percentage, in Excel and Google Sheets.
How to calculate monthly recurring revenue (MRR)
Learn how to calculate MRR in Excel and Google Sheets using SUMIF to sum active subscription revenue by billing period, normalized to a monthly figure.
How to calculate annual recurring revenue (ARR)
Calculate ARR in Excel and Google Sheets by summing normalized annual subscription revenue across all active accounts, converting monthly contracts to their annual equivalent.
How to calculate customer acquisition cost (CAC)
Calculate CAC in Excel and Google Sheets by dividing total sales and marketing spend by the number of new customers acquired in the same period.
How to calculate the CAC payback period
Calculate the CAC payback period in Excel and Google Sheets by dividing CAC by the monthly gross profit contribution per customer to find months to recover acquisition cost.
How to calculate monthly burn rate
Calculate monthly burn rate in Excel and Google Sheets by subtracting total monthly cash outflows from cash inflows, then averaging over recent months for a reliable run rate.
How to calculate cash runway in months
Calculate cash runway in months in Excel and Google Sheets by dividing current cash balance by average monthly net burn rate — a critical survival metric for startups.
How to calculate net revenue retention (NRR)
Calculate NRR in Excel and Google Sheets using the canonical formula: (Starting MRR + Expansion − Churn − Contraction) / Starting MRR, expressed as a percentage.
How to calculate gross revenue retention (GRR)
Calculate GRR in Excel and Google Sheets as (Starting MRR − Churn − Contraction) / Starting MRR — the revenue retained from existing customers, capped at 100%.
How to calculate the SaaS magic number
Calculate the SaaS magic number in Excel and Google Sheets: (Current Quarter ARR − Prior Quarter ARR) × 4 ÷ Prior Quarter S&M Spend — a sales efficiency benchmark.
How to calculate the SaaS rule of 40
Calculate the SaaS rule of 40 in Excel and Google Sheets: Revenue Growth Rate (%) + Profit Margin (%). A score ≥ 40 signals a healthy balance of growth and profitability.
How to calculate average revenue per user (ARPU)
Calculate ARPU in Excel and Google Sheets by dividing total recurring revenue for a period by the average number of active users — a key unit-economics benchmark.
How to calculate average revenue per account (ARPA)
Calculate ARPA in Excel and Google Sheets by dividing total MRR by the number of active paying accounts — the right unit-economics metric for B2B SaaS with multi-seat accounts.
How to calculate the SaaS quick ratio
Calculate the SaaS quick ratio (new MRR + expansion MRR) / (churned MRR + contraction MRR) in Excel and Google Sheets to measure revenue growth efficiency.
How to calculate the LTV-to-CAC ratio
Calculate the LTV-to-CAC ratio in Excel and Google Sheets using average revenue per customer, gross margin, churn rate, and average cost to acquire a customer.