How does growth compound across months?

Each month's spend is the previous month's spend multiplied by one plus the growth rate. Compounding means a steady percentage grows the absolute spend faster every month.

What does the efficiency rate model?

It captures the savings you expect from optimization — prompt trimming, caching, cheaper models. It reduces each month's cost by a steady percentage, partly offsetting growth.

What is the exit run rate?

It is the forecast spend in month 12, the rate you are running at as you enter the next year. It is usually a better planning number than the annual total when usage is growing.

Is my data sent anywhere?

No. The planner runs entirely in your browser. Nothing you enter is uploaded, stored or logged.

Annual AI Budget Planner

Annual AI budget planner

A single monthly API bill tells you little about where your AI spend is heading. Usage grows, but optimization claws some of it back. This planner projects a full 12-month forecast from your starting spend, your expected growth, and the efficiency gains you plan to ship — so you can put a defensible number in next year’s budget.

How it works

Each month combines two forces: growth pushes spend up, efficiency pulls it down. The planner applies both as compounding monthly rates:

month[n] = month[n-1] × (1 + growth_rate) × (1 − efficiency_rate)
annual   = sum of all 12 months
exit_run_rate = month[12]

Because both effects compound, small monthly rates produce large differences by December. A 10% monthly growth with no efficiency gain nearly triples spend across the year; a few points of monthly efficiency meaningfully flattens it.

Tips and notes

Plan to the exit run rate, not the average. If usage is growing, December’s spend is what carries into next year — budget for it.
Treat efficiency as a project, not a wish. Only count efficiency gains you have a concrete plan to ship; otherwise the forecast flatters you.
Re-forecast quarterly. Replace projected months with actuals as they land so the back half of the year stays honest.