Your API bill is not one number. It's a stack. AI calls, SMS, email, payments, maps, search, hosting, databases and monitoring all scale differently. Some costs are fixed; some grow with every user; some look harmless at 1,000 users and become the biggest line item at 100,000. This calculator models the full stack before you commit to an architecture.
—per utente/mese
—all'anno
—biggest line item
Your stack at different scales
Same services — watch fixed costs give way to per-user costs as you grow.
| Utenti | Total / month | Per utente |
|---|
⚠️ Editable estimates. Per-user costs are typical blended figures (usage × reference list prices, July 2026) — your real numbers depend on plan tiers, free allowances, caching and how heavily each user hits each API. Tune every field to your product. ·
Segnala prezzo obsoleto →
Why "cost per user" beats a flat monthly number
Early on, your bill is mostly fisso: hosting, a vector DB, a data subscription. Traffic is tiny, so per-user costs barely register. But as you grow, the per-user services — AI calls, SMS, maps, payments — scale linearly and quietly take over. The line item that was rounding error at 1k users can be your biggest bill at 100k. That flip is why a single monthly figure is misleading; the scale table above shows where your costs actually go as you grow.
Want to drill into one service? See the dedicated guides for OpenAI, Twilio, Banda E il riposo, model an AI feature on the Stima dei costi delle app AI, or price a support bot with the calcolatore dei costi del chatbot.
Rapporto prezzo-prestazioni dell'AICosto dello strumento di ricerca WebCosto dell'Assistente di codifica AILLM self-hosted e APIMonitoraggio della spesa AI
Come funziona questa calcolatrice
IL Calcolatore dei costi dello stack API estimates the total monthly cost of running the third-party APIs and cloud services behind your product, rather than the price of any single vendor. You enter your number of utenti attivi mensili and pick a preset, and the tool sums the recurring charges across a typical stack — OpenAI, Stripe, Twilio, SendGrid, Maps, a vector database, hosting, and more. The two main drivers are how many users you serve and how usage-heavy each service is per user, since most of these APIs bill by request, message, token, or transaction. It then projects the same stack at 1k, 10k, and 100k users so you can see how costs scale.
This matters because per-user costs rarely stay flat as you grow. The key trade-off to watch is which service dominates the bill: a cheap API at 1k users can become the largest line item at 100k, especially usage-metered ones like AI or messaging. Compare the presets and the three user tiers side by side to find where spending concentrates, so you can renegotiate, cache, or replace that service before scale makes it expensive.
Domande frequenti
How much does an API stack cost for a startup?
It depends entirely on which APIs you use and how heavily. A simple SaaS MVP can run under $100/month at low traffic, mostly fixed hosting and tooling. Add AI, SMS, maps and payments at tens of thousands of users and the per-user costs start to dominate — often $0.05 to $0.30 per active user per month. This calculator lets you toggle services and see the total at 1k, 10k and 100k users.
Which API usually costs the most at scale?
At low traffic, fixed costs (hosting, vector DB, data subscriptions) dominate. As users grow, the per-user services take over — typically LLM/AI calls, SMS, and maps, because they scale linearly with usage. The line items flip as you grow, which is exactly why a cost-per-user view matters more than a flat monthly number.