← Retour aux guides

Small-Team AI API Budgets: A Practical 2026 Guide

Budget for workflows, not headcount

Estimating monthly AI API costs for a small team starts with what people actually run. For a useful 2026 budget, separate coding assistance, document processing, customer-facing features, and experiments. Give each workflow its own usage assumptions instead of assigning everyone an arbitrary monthly allowance.

1. Count requests behind each task

Create a spreadsheet with these columns: workflow, active users, working days, tasks per user per day, model calls per task, average input tokens, average output tokens, and model rates.

Monthly calls = users × working days × daily tasks × calls per task. For example, five people completing ten AI-assisted tasks daily across twenty working days, with four calls per task, generate 4,000 calls. Include scheduled jobs separately so overnight automation does not disappear from your forecast.

2. Measure tokens with a representative pilot

Run a five-day pilot using normal documents, repositories, and conversations. Record request IDs, workflow names, model identifiers, token usage, and whether the result was accepted. OpenAI-compatible Chat Completions responses report prompt_tokens and completion_tokens; other endpoints use different field names. Cached input can have a separate rate, so preserve its breakdown. ([help.openai.com](https://help.openai.com/en/articles/4936856-understanding-and-counting-tokens))

Measure complete tasks, not just individual messages. Include follow-up calls and retries in the task totals. Capture both average cost and the 90th-percentile task cost to expose expensive outliers.

Also inspect reasoning usage. For example, Gemini 2.5 Flash pricing includes thinking tokens in output charges, so visible answer length alone is not a reliable billing estimate. ([ai.google.dev](https://ai.google.dev/gemini-api/docs/pricing.md))

3. Calculate each billing category separately

Token cost = (uncached input tokens × input rate + cached input tokens × cache-read rate + output tokens × output rate) ÷ 1,000,000. This assumes rates quoted per million tokens. Input, cached input, and output can have different prices; do not multiply total tokens by one blended rate unless you have calculated that blend from your actual workload. ([help.openai.com](https://help.openai.com/en/articles/4936856-understanding-and-counting-tokens))

For a simple worked example, assume 4,000 monthly calls averaging 3,000 input tokens and 750 billed output tokens. Use hypothetical rates of $0.50 per million input tokens and $2.00 per million output tokens:

• Input: 12 million tokens × $0.50 = $6.
• Output: 3 million tokens × $2.00 = $6.
• Total: $12 monthly, before additional charges.

These are illustrative rates, not a current 59API quotation. Add separate rows for any applicable cache writes, cache storage, search tools, media processing, payment fees, and taxes. Check the selected service's billing rules rather than assuming everything is included.

4. Build a realistic upper scenario

Calculate three cases: normal workload, doubled task volume, and expensive tasks with longer context or additional agent steps. In the example, doubling calls doubles the token subtotal to $24 if the token mix stays unchanged.

A 30% planning reserve would turn the $12 baseline into $15.60. Treat that percentage as a starting assumption, not protection against unlimited automation. Replace it with observed variability after the first month.

5. Compare the effective cost on 59API

59API is worth evaluating as a low-cost, pay-as-you-go option: it offers prepaid, per-token billing without a monthly subscription. Its shared service supports Claude Code, Codex, Gemini CLI, and OpenAI SDK workflows. It advertises official-model capability and offers referral rebates. Compare its current model-specific rates against your measured token mix rather than relying on a cheapest-provider headline. ([59api.com](https://59api.com/))

Run the same representative tasks through your shortlisted routes. Compare cost per accepted result, latency, and failure rate—not just price per million tokens. Keep referral income outside the operating budget until earned.

6. Control spending and reconcile weekly

Assign an owner to each workflow, separate development from production credentials, and set maximum agent steps and output limits. Configure alerts at chosen thresholds, but distinguish notifications from enforcement: spend alerts do not stop requests; hard limits are a separate control. Verify what your provider actually supports. ([developers.openai.com](https://developers.openai.com/api/docs/guides/spend-limits?utm_source=openai))

Each week, compare recorded usage with billed charges and update the forecast. If you want a practical starting point, sign up for 59API and test one representative workflow before expanding access across the team.

Tarifs · Docs