one-line definition
Unit economics describes the direct revenue and costs associated with acquiring and serving a single customer.
formula: LTV:CAC ratio = Customer lifetime value ÷ Customer acquisition cost (target: 3:1 or higher)
tl;dr
If your LTV:CAC ratio is below 1:1, you lose money on every customer. Above 3:1 means sustainable growth. Most solo founders should optimize for low CAC first (organic channels) rather than trying to raise LTV.
Simple definition
Unit economics answers a simple question: do you make more money from a customer than it costs to acquire and serve them? It boils your entire business model down to the relationship between two numbers — customer lifetime value (LTV) and customer acquisition cost (CAC). For solo founders, healthy unit economics is the difference between a side project that drains your bank account and a business that funds itself.
How to calculate it
LTV:CAC ratio = Customer lifetime value ÷ Customer acquisition cost
Start with a simplified LTV: Average monthly revenue per customer ÷ Monthly churn rate. Then divide by your CAC.
- Average revenue per customer: $39/mo
- Monthly churn rate: 5%
- LTV = $39 ÷ 0.05 = $780
- CAC (from Google Ads): $180
- LTV:CAC = $780 ÷ $180 = 4.3:1
A 4.3:1 ratio means you earn $4.30 for every $1 spent on acquisition — healthy and sustainable. Target 3:1 or higher before scaling any paid channel.
Example
You run a habit-tracking app with two acquisition channels. Google Ads brings customers at $120 CAC with an LTV of $200 (1.7:1 ratio — unprofitable). Your blog brings customers at $15 CAC (your writing time) with the same $200 LTV (13:1 ratio). The product is identical for both groups, but unit economics tells you to double down on content and pause ads. Scale the channel where the math works, not the one that feels more immediate.
Related reading
Related terms
- LTV
- CAC
- Payback Period
FAQ
When should I start tracking unit economics?+
As soon as you have 20-30 paying customers and at least one acquisition channel with measurable spend. Before that, focus on finding product-market fit — unit economics only matter when you have something people want.
What if my LTV:CAC ratio is below 3:1?+
Either reduce CAC (switch to organic channels, improve conversion rates) or increase LTV (reduce churn, add upsell paths). For solo founders, lowering CAC is usually faster and cheaper than raising LTV.