Calculate SaaS unit economics including MRR, ARR, LTV, CAC payback period, LTV:CAC ratio, net churn rate, and cash runway.
SaaS metrics use standard industry formulas: LTV = (ARPU × Gross Margin %) / Monthly Churn %; CAC Payback = CAC / (ARPU × Gross Margin %). Cash runway is estimated from current cash and net monthly burn (Total Spend - Gross Profit). Figures are illustrative planning estimates.
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SaaS Metrics Calculator calculates critical unit economics for subscription software businesses, including Monthly Recurring Revenue (MRR), Annual Recurring Revenue (ARR), Average Revenue Per User (ARPU), Customer Lifetime Value (LTV), Customer Acquisition Cost (CAC), CAC payback period, LTV:CAC ratio, monthly churn rate, and cash runway.
MRR: £20,000, Subscribers: 400 (ARPU £50), Churned: 8/mo (2% Churn), Gross Margin: 80% Marketing: £6,000/mo, New Subs: 30/mo (CAC £200) Result: LTV: £2,000 | LTV:CAC Ratio: 10.0x (Excellent) | CAC Payback: 5.0 months | Cash Runway: 18.5 months
An LTV:CAC ratio of 3x or higher is generally considered healthy for subscription software businesses. A ratio below 1x indicates losing money on customers, while a ratio above 5x may suggest under-investing in marketing growth.
Cash Runway (in months) is calculated as Current Cash Balance divided by Net Monthly Burn Rate (Operating Expenses + Marketing Spend minus Gross Profit).