How to Use AI Stack Cost Calculator
The AI Stack Cost Calculator takes each layer of your stack (hosting, database, auth, the AI model, email, and monitoring) plus your token usage per call, then projects per-user and total cost at several scale tiers. It names the single dominant cost driver so you know where to negotiate or re-architect first.
What It Does
Use the calculator with intent
The AI Stack Cost Calculator takes each layer of your stack (hosting, database, auth, the AI model, email, and monitoring) plus your token usage per call, then projects per-user and total cost at several scale tiers. It names the single dominant cost driver so you know where to negotiate or re-architect first.
Solo founders and small teams planning an AI-powered product who need a realistic monthly cost before committing to a stack, and who want to know whether the AI API or the infrastructure will dominate the bill as they grow.
Interpreting Results
Start with the dominant cost driver and its percent share, then read per-user cost at the tier closest to your real user count. A stack where one component is over half of total spend is the clearest place to cut; a stack where cost per user falls sharply between tiers is benefiting from fixed-cost amortization and rewards growth.
Input Steps
Field by field
- 1
Pick each stack layer
Select your hosting, database, auth, email, and monitoring providers from the presets, or enter a custom monthly cost for any layer where you already have a quote. Leave a layer at the free tier (index 0) if you are not paying for it yet.
- 2
Set the AI model and token usage
Choose the AI model or enter custom input/output prices per million tokens, then set average input and output tokens per call and API calls per user per day. These four numbers drive the variable cost that grows with usage, so use real averages from your prompts, not round guesses.
- 3
Add fixed extras
Enter the yearly domain cost and any other flat monthly costs (a paid analytics seat, a Slack workspace). These spread thin per user at scale but matter a lot at launch when you have few users.
- 4
Read the scale tiers and dominant driver
Read total and per-user cost across the user tiers and note the dominant cost driver and its percent share. If the AI API dominates, token efficiency and caching are the fix that moves the bill most; if a fixed service dominates at low scale, you are paying platform minimums before you have users to amortize them.
- 5
Re-run as usage changes
Re-run when your token usage per call, calls per user, or provider tier changes. Recheck the dominant driver at each tier, since the component that dominates at 100 users is often not the one that dominates at 10,000.
Common Scenarios
Use realistic starting points
Pre-launch on free tiers
Hosting / Database / Auth
Free tier (index 0)
API calls per user per day
5
Domain cost yearly
15
At a handful of users the AI API and the domain are nearly the whole bill. Watch how cheap the early tier is so you do not over-provision paid infrastructure before you have demand.
AI-API-dominated at scale
API calls per user per day
20
Avg output tokens
1000
AI model
Mid-tier flagship
When the dominant cost driver is the AI API at 10,000 users, watch how the percent share moves if you halve output tokens or switch to a cheaper model. That single change usually beats any infrastructure saving.
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FAQ
Questions people ask next
The short answers readers usually want after the first pass.
Sources & References
- Gemini API pricing — Google
- Claude API pricing — Anthropic
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