AI agent cost calculator: a monthly and first-year budget

Start with the calculator's six inputs

The model asks for setupCost, platformMonthly, tasksMonthly, modelPerTask, reviewHoursMonthly and reviewHourlyCost. Define a task as one unit of work a business actually wants completed, such as a triaged request or a drafted answer. The same definition must be used in your volume forecast and per-task estimate. The task count must be a positive whole number. Enter money in one currency; the calculator does not convert it. Setup is a one-time cost, while the platform, task and review amounts describe one month.

The exact monthly equation is platformMonthly + tasksMonthly × modelPerTask + reviewHoursMonthly × reviewHourlyCost. The first-year equation is setupCost + 12 × monthly total, assuming each month has the same activity. Cost per task is the full monthly total divided by tasksMonthly. That last figure spreads platform and review expense across tasks; it is not the marginal API price of one extra task.

Estimate model cost per task from real usage

A task might use several model calls, long context, retries or a paid tool. The calculator has no individual token, step, retry or tool fields. Investigate these components in a pilot and consolidate the resulting billable variable expense into modelPerTask, using the same task boundary as the forecast. OpenAI and Anthropic publish separate input and output pricing and tool-related conditions in their official documentation; these sources explain why a generic price for an ‘AI agent’ is unreliable. Use the product, region, tier and contract that apply to you.

If third-party tools or search are billed outside the model account and you cannot attribute them per task, disclose them as excluded instead of implying the result covers them. Averages can hide a small group of very expensive tasks, so compare ordinary and difficult cases. Preserve the pilot's token and call log as support for your single per-task input; that detailed ledger is an input-estimation method, not a second calculator formula.

A hypothetical example that matches the fields

Assume a fictional setupCost of $3,500 and platformMonthly of $180. Plan 1,200 tasksMonthly at an invented modelPerTask of $0.08. Suppose reviewers spend 12 hours a month and the assumed reviewHourlyCost is $35. These are arithmetic examples, not a provider rate card or evidence of a customer's results. Model spending is 1,200 × $0.08 = $96 per month. Review spending is 12 × $35 = $420. Add the platform's $180 to obtain a monthlyTotal of $696.

Twelve identical months cost 12 × $696 = $8,352. Add the one-time $3,500 setup for a firstYearTotal of $11,852. The displayed costPerTask is $696 ÷ 1,200 = $0.58, which includes the monthly platform and review allocation but not setup. At 1,500 tasks, if the review hours and platform fee truly stay fixed, the model line becomes $120 and the monthly total $720. Confirm whether review hours would actually remain at 12 before using that scenario.

Review work deserves its own line

A fluent response may still need approval, correction, escalation or a quality audit. Estimate reviewHoursMonthly from a sample of tasks and include routine review, not just exceptional incidents. reviewHourlyCost should reflect the cost basis your team wants to budget, consistently applied; this worksheet does not infer wages or overhead. If the team expects review work to scale with volume, change the hours when you change tasksMonthly. Holding hours fixed during a growth scenario is a visible assumption, not a built-in forecast.

Do not place the same human cost in both modelPerTask and the review inputs. The modelPerTask field is intended here for attributable variable technology use, and review inputs for human time. If a vendor's platform fee already bundles model usage, avoid charging it again. Check the contract boundary before entering numbers.

State what the result leaves out

The six inputs do not directly model taxes, data storage, network transfer, evaluation infrastructure, legal review, privacy work, incident response or later integrations. Include a known recurring expense in platformMonthly only if that is genuinely how you choose to group it, then say so. SetupCost may cover initial integration and data preparation, but it is not automatically a complete launch budget. The result also assumes a constant monthly task mix and does not model contractual minimums or changing tier rates.

Because the calculator reports first-year cost as a simple twelve-month projection, a seasonal business should run several scenarios or calculate months separately outside it. Save the date of the rates and assumptions. A useful budget can be reconciled against bills and hours after launch; a precise-looking output from guessed inputs cannot.

Use the estimate to decide what to pilot

Compare an expected task volume with a plausible peak, using the same six fields each time. Ask what fraction of tasks requires a person, whether tools are included in the per-task number and who pays for failed attempts. Pair the spending forecast with measured completion quality and time saved. A small model bill alone does not prove that the workflow pays for itself. After a month, update modelPerTask from actual usage, reviewHoursMonthly from timesheets and platformMonthly from invoices. Keep setup separate so recurring efficiency is not distorted by a one-time project.