LTV:CAC Ratio
The ratio of customer lifetime value to customer acquisition cost — indicating whether acquiring customers is a profitable investment.
What is LTV:CAC Ratio?
The LTV:CAC ratio compares how much a customer is worth over their lifetime to how much it costs to acquire them. A ratio of 3:1 means every dollar spent on acquisition returns three dollars in customer revenue.
The widely accepted benchmark for healthy SaaS businesses is an LTV:CAC ratio of 3:1 or higher. A ratio below 1:1 means you're losing money on every customer. A ratio above 5:1 might mean you're underinvesting in growth — you could afford to spend more on acquisition and grow faster.
LTV:CAC is the single metric that best captures whether a business model works. It combines retention (via LTV), pricing (via LTV), and go-to-market efficiency (via CAC) into one number.
Why it matters
LTV:CAC is the metric that tells you whether to accelerate or pump the brakes. A high ratio (4:1+) means pouring money into acquisition is a great investment — every dollar yields four in return. A low ratio (1.5:1 or below) means you need to improve retention or pricing before scaling.
Investors love this metric because it predicts the future. A startup with a 4:1 LTV:CAC ratio and a clear acquisition channel can confidently project profitable growth. A startup with a 1.2:1 ratio is one bad month from losing money on every customer.
Formula
LTV:CAC Ratio = Customer Lifetime Value / Customer Acquisition Cost
Example
LTV = $6,000. CAC = $1,800. LTV:CAC = 3.3:1. This is healthy. If you reduce churn by 20% (increasing LTV to $7,500) and optimize ad spend (reducing CAC to $1,500), the ratio improves to 5:1 — signaling you can invest more aggressively in growth.
Common mistakes
- 1Using revenue-based LTV instead of gross-margin-based LTV (the latter is more accurate because it subtracts delivery costs)
- 2Not calculating LTV:CAC by customer segment (your enterprise segment might be 5:1 while SMB is 1.5:1)
- 3Treating LTV:CAC as a static number instead of tracking it over time
Build a business model that scales
RunwayCal helps you track the revenue and cost metrics that feed into LTV:CAC — connecting unit economics to runway.
Get financial clarity → Start free