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

AI cost per user/month ($)

API calls for one user in a typical month. A penny per call x 100 calls = $1.

Infrastructure per user/month ($)

Hosting, database, email, etc. divided by user count. At 100 users and $10/mo infra, that's $0.10.

Support per user/month ($)

Your time handling support. At zero users, this is $0. At 100+, estimate it.

Other per user/month ($)

Payment processing (Stripe takes ~3%), third-party services, etc.

Your revenue

Price per user/month ($)

What you charge. If annual, divide by 12.

Fixed monthly costs ($)

Costs you pay regardless of user count: domain, base hosting tier, subscriptions.

Free-to-paid conversion rate

Of people who sign up, how many pay? 2-5% is typical for freemium. 100% if no free tier.

Monthly churn rate

% of paying users who cancel each month. Under 5% is good. Over 10% is a problem.

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.