SaaS Unit Economics Calculator
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Monthly Recurring Revenue (MRR)
ARR (Annualized)$0
Active Customers0
Customer Lifetime (Months)0
LTV (Lifetime Value)$0
Gross Margin0%
Net Monthly Profit$0
CAC Payback Period--
LTV:CAC Ratio--
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How to Use
Start by entering your monthly price per user and the number of current customers. Then input how many new customers you add each month and your monthly churn rate (the percentage of customers who cancel each month).
Enter your COGS (cost of goods sold) per customer each month — this includes hosting, support, and infrastructure costs. Add your fixed monthly costs (salaries, office, software) and sales & marketing spend. Finally, enter your CAC (customer acquisition cost).
A healthy SaaS business typically has an LTV:CAC ratio above 3:1, a CAC payback period under 12 months, and gross margins above 70%.
SaaS Metrics Formulas
MRR = (Price × Customers) + (New Customers × Price)
ARR = MRR × 12
Customer Lifetime = 1 / Churn Rate
LTV = ARPU × Customer Lifetime
Gross Margin = (ARPU − COGS) / ARPU × 100
CAC Payback = CAC / (ARPU − COGS)
LTV:CAC = LTV / CAC
ARR = MRR × 12
Customer Lifetime = 1 / Churn Rate
LTV = ARPU × Customer Lifetime
Gross Margin = (ARPU − COGS) / ARPU × 100
CAC Payback = CAC / (ARPU − COGS)
LTV:CAC = LTV / CAC
Frequently Asked Questions
A ratio above 3:1 is considered healthy and indicates your business generates sufficient value from each customer relative to what it costs to acquire them. Below 1:1 means you are spending more to acquire customers than they will generate in revenue.
To shorten CAC payback, you can: increase your price, reduce churn, improve sales efficiency, optimize marketing channels, implement self-serve onboarding, or increase average contract value. Most investors want to see a payback period under 12 months.
Monthly churn rates vary by segment: enterprise SaaS averages 1-2%, SMB SaaS averages 3-7%, and B2C subscription apps can see 5-10% monthly churn. Reducing churn by even 1% can significantly improve LTV.
Yes, fixed monthly costs should include all operational expenses that do not vary directly with the number of customers: salaries, rent, software subscriptions, insurance, and administrative costs. COGS should only include costs that scale with each additional customer.