What a micro-SaaS actually costs to run
A paying AI app on the default indie stack — Vercel, Supabase, Resend, Stripe, plus an LLM API — costs about $25.98/month at 100 users,$79.84 at 1,000 and $663 at 10,000, assuming 5% of users pay $29/month. Every figure below is computed from the providers' published tiers (verified 2026-09-10) and the index's cross-checked LLM prices — and you can re-run it on your own numbers.
The bill at 100, 1,000 and 10,000 users
| Line | 100 users | 1,000 users | 10,000 users |
|---|---|---|---|
| LLM API (DeepSeek V4 Flash 0731 (DeepInfra)) | $0.28 | $2.79 | $27.90 |
| Hosting — Vercel Pro | $20.00 | $20.00 | $20.00 |
| Database — Supabase | $0.00 | $0.00 | $25.00 |
| Email — Resend | $0.00 | $0.00 | $20.00 |
| Payments — Stripe (2.9% + $0.3) | $5.71 | $57.05 | $571 |
| Total / month | $25.98 | $79.84 | $663 |
Assumptions: 25 AI requests/user/month (chat profile: 1200 in /400 out tokens, 60% cached), 12 pageviews/user,3 transactional emails/user, 500 KB stored/user, 5% paying $29/mo. Medians, not measurements — adjust every one of them in the calculator.
Where the money actually goes
Three things decide the bill, and none of them is what most builders expect. First, the floor is $20/month, not $0: Vercel's Hobby plan is non-commercial only, so the moment you charge users you are on Pro — the free tiers of Supabase (0.5 GB,50k auth users) and Resend (3,000 emails/month) hold much longer. Second, the LLM line is small if you pick well: on the current best intelligence-per-dollar model it stays under hosting cost up to about 1,000 users — but swap in a frontier flagship and it becomes the whole bill, which is why the LLM calculatorranks all tracked endpoints on your workload. Third, past roughly 1,000 users your biggest line is Stripe, because payment fees scale with revenue rather than traffic — at 10,000 users the 2.9% + $0.3 per transaction comes to $571/month. That one you should be glad to pay.
When each free tier runs out
Under the same assumptions: Supabase's free tier is exhausted by database storage around 1,000 users (0.5 GB at 500 KB/user) long before its 50k-user auth limit; Resend's3,000-email tier lasts to exactly 1,000 users at 3 emails/user; and Vercel Hobby was never available to a commercial app in the first place. Thecalculator computes these thresholds live for whichever stack you pick — including Netlify, Cloudflare, Railway, Neon, Turso, PlanetScale, Postmark, SES and merchant-of-record payment options.
→ Run your own numbers in the stack cost calculator
FAQ
How much does it cost to run an AI micro-SaaS with 1,000 users?
Around $79.84 per month for a typical stack — Vercel Pro ($20.00), Supabase ($0.00), Resend ($0.00), the LLM API ($2.79 on DeepSeek V4 Flash 0731 (DeepInfra)) and Stripe fees ($57.05 on 5% of users paying $29/mo). Payment processing, which scales with revenue, is usually the biggest line — a good problem to have.
What is the minimum monthly cost of a commercial app on this stack?
About $20/month. Vercel's free Hobby plan is restricted to non-commercial use, so any app that charges users starts on Pro at $20/seat. Database, email and the LLM API can all sit in free tiers at low traffic; payment fees only exist once you have revenue.
Is the LLM API the expensive part of running an AI app?
Usually not, if you pick well. At 1,000 users making 25 AI requests each per month, the LLM line is $2.79 on the current best intelligence-per-dollar model — less than hosting. Choosing a frontier flagship instead can multiply that line by 100x or more, which is exactly what the calculator lets you test per model.
Sources: each provider's published pricing page, hand-verified 2026-09-10 (linked per line in the calculator and in the raw dataset /api/stack-pricing.json, CC BY 4.0). LLM prices from the index's daily cross-checked pipeline.