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AI budget capacity planner

Daily API Budget Planner

Turn a monthly AI API budget and estimated request cost into safe daily, monthly, and per-user request limits.

Reserved budget bufferDaily and per-user limitsHigh-cost request warnings

API budget limits

Convert a monthly budget into practical request limits.

$
$
%

Held back from the spendable monthly budget.

Daily API budget plan

Safe request limits after budget reserve

Safe monthly budget

$425.00

Daily budget

$14.17

Allowed requests per month

85,000

Allowed requests per day

2,833

Requests per active user per day

2

Calculation basis

Original monthly budget
$500.00
Reserved buffer amount
$75.00
Estimated cost per request
$0.005

Formula

How API request limits are calculated

The reserve percentage is removed from the monthly budget before request limits are calculated from the estimated cost per request.

Safe monthly budget = monthly budget × (1 − reserve %)

Daily budget = safe monthly budget ÷ days per month

Requests per active user = floor(daily budget ÷ request cost ÷ active users)

daily-budget.ts
export function requestLimits(input: {
  monthlyBudget: number;
  costPerRequest: number;
  activeUsersPerDay: number;
  daysPerMonth: number;
  reservePercent: number;
}) {
  const safeBudget =
    input.monthlyBudget * (1 - input.reservePercent / 100);
  const dailyBudget = safeBudget / input.daysPerMonth;
  const requestsPerDay =
    Math.floor(dailyBudget / input.costPerRequest);

  return {
    safeBudget,
    dailyBudget,
    requestsPerDay,
    requestsPerUser:
      Math.floor(requestsPerDay / input.activeUsersPerDay),
  };
}

Example API budget plan

A $500 monthly budget with a 15% reserve leaves $425 available for planned usage. At half a cent per request, that supports about 85,000 requests per month.

Use observed production request cost when available. Average request cost can change with prompt length, outputs, caching, retries, and tool calls.

What this estimate includes

  • Reserved and spendable monthly budget
  • Daily budget based on selected month length
  • Monthly and daily request capacity
  • Per-active-user daily request allowance

Frequently asked questions

Why reserve part of the API budget?

A reserve reduces the chance that traffic spikes, longer outputs, retries, or pricing changes exhaust the full monthly budget.

Where do I get cost per request?

Use the text-token, image, or audio calculator with a representative workload, then copy the estimated per-request or per-run cost.

Should request limits be rounded down?

Yes. Capacity limits use whole requests and round down so the estimate does not intentionally exceed the safe budget.

Does this replace provider billing limits?

No. Configure provider budgets, alerts, quotas, and application-side rate limits in addition to this planning estimate.