Unit Economics Calculator
Calculate CAC, LTV, LTV:CAC ratio, and payback period for SaaS and subscription businesses. Enter values for instant results with step-by-step formulas.
Formula
LTV = ARPU x (1 / Churn Rate) x Gross Margin | LTV:CAC = LTV / CAC | Payback = CAC / (ARPU x Margin)
LTV estimates total profit from a customer over their lifetime. The LTV:CAC ratio shows return on acquisition spend. Payback period indicates months to recover acquisition cost from gross profit.
Worked Examples
Example 1: B2B SaaS Startup Analysis
Problem: A SaaS company has CAC of $200, ARPU of $60/month, 4% monthly churn, and 75% gross margin. Calculate unit economics.
Solution: Average Lifespan = 1 / 0.04 = 25 months\nLTV = $60 x 25 = $1,500\nMargin-Adjusted LTV = $1,500 x 0.75 = $1,125\nLTV:CAC Ratio = $1,125 / $200 = 5.63\nPayback Period = $200 / ($60 x 0.75) = 4.4 months\nROI = ($1,125 - $200) / $200 = 462.5%
Result: LTV: $1,500 | LTV:CAC Ratio: 5.63x | Payback: 4.4 months
Example 2: Consumer Subscription Service
Problem: A streaming service has CAC of $30, ARPU of $12/month, 8% monthly churn, and 60% gross margin. Evaluate viability.
Solution: Average Lifespan = 1 / 0.08 = 12.5 months\nLTV = $12 x 12.5 = $150\nMargin-Adjusted LTV = $150 x 0.60 = $90\nLTV:CAC Ratio = $90 / $30 = 3.0\nPayback Period = $30 / ($12 x 0.60) = 4.2 months\nROI = ($90 - $30) / $30 = 200%
Result: LTV: $150 | LTV:CAC Ratio: 3.0x | Payback: 4.2 months
Frequently Asked Questions
What are unit economics and why do they matter?
Unit economics analyze the direct revenues and costs associated with a particular business model on a per-unit basis, typically per customer or per transaction. They help founders and investors understand whether a business can be profitable at scale by examining the fundamental economic relationship between what it costs to acquire a customer and how much revenue that customer generates. Strong unit economics mean each customer contributes positively to the bottom line, while poor unit economics suggest the business loses money on every customer acquired. This analysis is essential for SaaS companies, subscription businesses, and marketplaces where customer lifetime value must exceed acquisition costs for the model to work.
How does churn rate impact unit economics?
Churn rate has a dramatic and often underestimated impact on unit economics because it directly determines the average customer lifespan, which in turn determines lifetime value of each customer. A seemingly small difference in monthly churn can have enormous effects on LTV calculations. For example, reducing monthly churn from 5 percent to 3 percent increases average customer lifespan from 20 months to 33 months, boosting LTV by 67 percent without changing pricing at all. High churn rates compress customer lifespans, reduce lifetime value, and make it increasingly difficult to maintain a healthy LTV to CAC ratio. This is why investor due diligence often focuses heavily on retention metrics and churn trends.
How do gross margins affect unit economics analysis?
Gross margin represents the percentage of revenue remaining after deducting the direct costs of delivering the product or service, and it significantly impacts the true profitability of each customer relationship. A company with $100 ARPU but only 50 percent gross margin generates $50 in gross profit per customer per month, while one with $80 ARPU and 85 percent gross margin generates $68 per month in actual profit contribution. Software businesses typically have gross margins of 70 to 85 percent, while services-heavy businesses may have margins of 30 to 50 percent due to higher delivery costs. When calculating LTV for unit economics purposes, you should always use the margin-adjusted figure to get an accurate picture of customer profitability.
When should a startup worry about unit economics?
Startups should begin tracking unit economics from the moment they start acquiring paying customers, even if the numbers are initially unfavorable during the early growth phase. In the earliest stages, it is acceptable for unit economics to be negative as the company invests heavily in product development and initial market penetration to establish a foothold. However, there should be a clear path to improving these metrics over time through increased pricing power, reduced churn, or improved acquisition efficiency as the business matures. By the time a startup reaches Series A fundraising, investors will expect to see improving unit economics trends and a reasonable timeline to achieving an LTV to CAC ratio of 3 or better.
How do you benchmark unit economics against competitors?
Benchmarking unit economics requires comparing key metrics like CAC, LTV, LTV to CAC ratio, payback period, and churn rates against industry averages and publicly available data from similar companies. SaaS industry reports from organizations like OpenView Partners, KeyBanc Capital Markets, and Bessemer Venture Partners publish annual surveys with median metrics across different company sizes and growth stages. For consumer businesses, typical CAC ranges from $5 to $50 while enterprise SaaS CAC can range from $5,000 to $50,000 or more per customer acquired. It is important to compare against companies at similar stages and in similar markets, since a B2B enterprise company will naturally have different unit economics than a consumer mobile application.
How do significant figures affect unit conversions?
Your converted result should have the same number of significant figures as your original measurement. If you measure 5.2 inches (2 significant figures), converting to centimeters gives 13 cm, not 13.208 cm. Using excessive decimal places implies false precision.