Unit Economics Calculator
Three numbers on a napkin: what each user costs you, what you charge them, and how many you need to make it work. The math that decides whether this is a business or a hobby.
Your costs per user
API calls for one user in a typical month. A penny per call x 100 calls = $1.
Hosting, database, email, etc. divided by user count. At 100 users and $10/mo infra, that's $0.10.
Your time handling support. At zero users, this is $0. At 100+, estimate it.
Payment processing (Stripe takes ~3%), third-party services, etc.
Your revenue
What you charge. If annual, divide by 12.
Costs you pay regardless of user count: domain, base hosting tier, subscriptions.
5%
Of people who sign up, how many pay? 2-5% is typical for freemium. 100% if no free tier.
5%
% of paying users who cancel each month. Under 5% is good. Over 10% is a problem.
Your unit economics
Cost breakdown per user
At scale
What this means
These are napkin numbers. They tell you whether the math can work, not whether it will. The inputs you are least sure about -- AI cost per user and conversion rate -- are the ones that matter most. If the math only works with optimistic assumptions, it does not work yet. For the full cost breakdown by user count, see Sign Up & Payments in the playbook.
Builder's Path is a public lab from Sellhausen AI Systems focused on AI-native building, validation, and product judgment.