LTV to CAC Ratio Calculator
The LTV:CAC ratio is the single most important metric for evaluating the efficiency and sustainability of a business model. It tells you whether the long-term value of your customers justifies the cost of acquiring them. Enter your average monthly revenue per customer, gross margin, monthly churn rate, and CAC to get your LTV, LTV:CAC ratio, and CAC payback period. A healthy 3:1 or higher ratio confirms your unit economics work.
LTV and LTV:CAC formulas
Customer Lifetime (months) = 1 / Monthly Churn Rate
LTV (Revenue) = Average Monthly Revenue per Customer / Monthly Churn Rate
LTV (Gross Profit) = LTV (Revenue) x (Gross Margin / 100)
LTV:CAC Ratio = LTV (Gross Profit) / CAC
CAC Payback Period (months) = CAC / (Average Monthly Revenue per Customer x Gross Margin / 100)
These are the standard SaaS metrics formulas. Gross profit LTV is preferred over revenue LTV for the ratio because it reflects actual economic value after the cost of delivering the service.
Improving your LTV:CAC ratio
- Reduce churn: even a 0.5% reduction in monthly churn significantly extends customer lifetime and multiplies LTV.
- Increase average revenue per customer through upselling, cross-selling, and usage-based pricing tied to customer success.
- Improve gross margin by reducing cost of goods sold: infrastructure optimization, supplier renegotiation, or product efficiency improvements.
- Reduce CAC through better lead quality (tighten targeting), improved conversion rates (optimize sales process), and lower-cost acquisition channels (referrals, SEO, partner programs).
- Segment your LTV:CAC by customer type (enterprise vs. SMB, by industry, by acquisition channel) to find which segments have the best economics and invest accordingly.
LTV to CAC ratio: frequently asked questions
What is the LTV to CAC ratio?
The LTV:CAC ratio compares the lifetime value of a customer (LTV, the total revenue or profit a customer generates over their relationship with you) to the cost of acquiring that customer (CAC). An LTV:CAC ratio of 3:1 means you earn $3 in lifetime value for every $1 spent acquiring a customer. It is the most important efficiency metric for subscription and recurring revenue businesses.
What is a good LTV to CAC ratio?
A ratio of 3:1 is widely cited as a healthy benchmark for SaaS and subscription businesses. Above 3:1 indicates strong unit economics. A ratio below 1:1 means you are spending more to acquire customers than they are worth over their lifetime, which is unsustainable without external funding. A ratio above 5:1 may suggest you are underinvesting in growth and leaving money on the table.
How do I calculate LTV?
The simplest LTV formula for subscription businesses is: LTV = Average Revenue per Customer per Period / Churn Rate per Period. For example, if average monthly revenue per customer is $100 and monthly churn is 2%, LTV = $100 / 0.02 = $5,000. For non-subscription businesses, LTV = Average Order Value x Purchase Frequency x Average Customer Lifespan.
What is the payback period for CAC?
CAC payback period = CAC / (Average Monthly Revenue per Customer x Gross Margin). It measures how many months it takes to recover your customer acquisition investment. A payback period below 12 months is generally considered healthy; above 18 months can strain cash flow, especially in capital-constrained businesses.
How do I improve my LTV:CAC ratio?
Improve LTV by reducing churn (extends customer lifetime), increasing average revenue per customer (upselling, price increases), and improving gross margin (reducing COGS). Reduce CAC by improving marketing efficiency, optimizing ad campaigns, investing in organic channels (SEO, content, referrals), and improving sales conversion rates.
Official sources
- U.S. Securities and Exchange Commission: Non-GAAP Financial Measures (LTV and CAC are commonly disclosed in SaaS company SEC filings).
- U.S. Small Business Administration: Marketing and Sales Guide.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.