Set a per-call price from your cost and target margin.
If a few endpoints cost far more to serve, a flat rate lets heavy users erode your margin. Meter usage and set overage rates. Model your own upstream spend first on the API request cost calculator.
The API Pricing / Monetization Calculator turns your unit cost into a sell price and a profit figure. You enter your cost per 1,000 calls, a target gross margin, and your billable calls per month, and it derives the price you should charge per call (or per thousand) so that the margin holds, then multiplies the per-call profit by your monthly volume to show total gross profit. The two biggest drivers are your underlying cost per call and the margin you target: a higher cost or a thinner margin pushes the price up, while volume scales the absolute profit without changing the per-call math.
The key trade-off to watch is margin versus volume. A high target margin raises your price and protects each call, but a price that sits above competitors can suppress the call volume that actually generates profit. Re-run the calculator with a lower margin and a realistically higher volume to see whether cheaper, higher-usage pricing earns more total profit than a premium rate. Also confirm your cost per 1,000 calls includes every real expense—compute, bandwidth, and third-party fees—so the margin you set reflects true profit rather than an incomplete cost base.
Start from your true cost per call (compute, upstream APIs, support), then divide by one minus your target margin. For 80% margin, price at five times cost. Add tiered plans and overage rates so heavy users pay proportionally.
Flat monthly tiers are simple but bleed margin on heavy users; pure usage-based scales with cost but is harder to forecast for buyers. Most successful APIs combine a tier (with an included quota) plus per-call overage above it.