API Request Cost Calculator
Many APIs and gateways price by request count. Use this calculator to estimate monthly request cost from your volume and per-million pricing, then compare baseline vs peak traffic.
Inputs
Requests (per month)
Avg 190.36 req/sec.
Avg RPS
Use steady-state throughput.
Est 315,187,200 requests/month.
Price ($ / 1M requests)
~$1,000.00 per 1B requests.
Scenario presets
Results
Estimated monthly request cost
$500.00
Requests
500,000,000
Billable requests: the detail that changes the estimate
- Confirm what the provider counts as a billable request (cache hits, errors, internal calls can differ).
- Split request classes if pricing differs (for example, authenticated vs unauthenticated, edge vs origin).
- Keep a baseline and peak scenario: retries and incident behavior can multiply request counts.
How teams reduce request-driven cost
- Caching: reduce repeat calls (browser, edge/CDN, server-side caching).
- Batching: fewer round trips for chatty clients.
- Payload shaping: smaller responses often unlock caching and reduce downstream compute too.
API-specific request accounting
- Split prod vs non-prod environments and sum them explicitly.
- Include auth, validation, and preflight calls if they are billed.
- Separate internal service-to-service calls from user traffic.
Worked request estimate from business events
- Monthly active users x sessions per user = sessions/month.
- Sessions/month x requests per session = requests/month.
- Add a retry factor (for example, 1.2x) for timeouts.
API request taxonomy (what to count)
- REST vs GraphQL: batch queries can hide request volume.
- Pagination and polling can multiply calls per session.
- Webhooks and callbacks add non-user traffic.
- Search and autocomplete endpoints are often the busiest routes.
API data sources
- Gateway analytics: request counts by stage/environment.
- API logs: per-endpoint volume for hot routes.
- Client telemetry: retries and timeout-driven bursts.
- Internal traffic: service-to-service requests that never hit the edge.
Result interpretation
- Small request deltas compound quickly at scale.
- Spikes usually come from retries, auth failures, or noisy clients.
Common mistakes
- Using a single average and ignoring peak or incident scenarios.
- Missing internal service-to-service calls in request totals.
- Ignoring health checks, preflight, or retry traffic that is billable.
Advanced inputs to capture
- Normalize per-10k vs per-1M pricing units before estimating.
- Separate endpoint or method mixes if rates differ.
- Add a retry or error multiplier to request volume.
- Split cache hits from origin requests when applicable.
Traffic scenarios
| Scenario | Requests | Endpoint mix | Retry factor |
|---|---|---|---|
| Steady | Expected | Normal mix | Low |
| Surge | High | Auth-heavy | High |
Validate after changes
- Compare API request counts to the billing usage type for requests.
- Check per-endpoint dashboards after releases or throttling changes.
Next steps
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Example scenario
- 500,000,000 requests/month at $1.00 per 1M requests ~ $500/month.
- Peak 180% scenario turns 500M into 900M requests for budget planning.
Included
- Request-fee estimate from requests/month and $ per 1M requests pricing.
- Optional RPS-based request estimator.
- Baseline vs peak scenario table for traffic spikes.
- Useful for API gateways, serverless, and request-metered services.
Not included
- Data transfer/bandwidth costs (model separately).
- Minimums, free tiers, and tiered steps unless you reflect them in inputs.
How we calculate
- Request cost = (requests per month / 1,000,000) x price per million requests.
- Use your provider's definition of billable requests and any request classes.
- This tool ignores data transfer; model bandwidth separately if relevant.
FAQ
Should I use total requests or only billable requests?
Use billable requests (some providers exclude cache hits, errors, or internal calls depending on the product).
How do I estimate monthly requests?
Convert from RPS using the RPS to Monthly Requests tool, or use your analytics.
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Disclaimer
Educational use only. Not legal, financial, or professional advice. Results are estimates based on the inputs and assumptions shown on this page. Verify pricing and limits with your providers and documentation.
Last updated: 2026-02-07