Convert API calls (or units) and cost per 1K into estimated monthly API cost.
Overview
Third-party APIs often charge per thousand calls. Product traffic can turn a small unit price into a large bill.
Enter API calls/units and cost per 1K. Estimated cost = (units ÷ 1000) × rate.
Watch for tiered pricing—above certain volumes the per-1K rate may drop; model each tier separately if needed.
Steps
Calls or billable units for the period.
Vendor price for each thousand.
Review estimated API cost.
Sum costs if endpoints have different rates.
Lower units to see savings from cache hits.
Math
estimatedCost = (tokens / 1000) × costPer1k
Same linear per-1K model used for token and AI usage costing.
Worked cases
250×0.50 = $125
$125 estimated cost.
2,000×0.50 = $1,000
$1,000 estimated cost.
250×0.20 = $50
$50 estimated cost.
Why use this
Questions