Estimate CloudWatch metrics API requests (dashboards and polling)

Metrics API request costs (GetMetricData and similar calls) can become meaningful when dashboards and tools poll frequently. A good estimate is based on refresh behavior, not on guesswork.

API request estimate inputs

Dashboards: refresh rate x widgets per dashboard.
GetMetricData: queries per page/view or job.
Alarms: evaluation frequency adds API calls.

Step 1: inventory the callers

CloudWatch dashboards: human views + wallboards + auto-refresh.
Third-party tools: Grafana, NOC tooling, custom scripts polling metrics.
Automations: scheduled jobs that pull metrics for reports and capacity planning.

Step 2: estimate requests from dashboards (fast model)

Rough model: API requests/day ~= views/day × refreshes/view × widgets/dashboard × queries/widget

Views/day: how often dashboards are opened (include wallboards as continuous views).
Refreshes/view: depends on refresh interval and typical session duration.
Widgets: number of widgets per dashboard.
Queries/widget: many widgets query multiple metrics (dimensions, percentiles, multiple series).

Step 3: include tools polling (often the hidden driver)

List each tool and its refresh interval (e.g., every 10s, 30s, 60s).
Estimate metrics queried per refresh (dashboards, panels, and alert evaluations).
Multiply by number of users or number of running instances (for distributed polling setups).

Add an incident multiplier

During incidents, engineers open multiple dashboards and run many ad-hoc investigations. For planning, include a “busy day” factor (for example, 5–10× normal dashboard views).

Worked example (order-of-magnitude)

Dashboards: 40 views/day
Refreshes per view: 6 (10-minute session with ~2-minute refresh)
Widgets: 24 per dashboard
Queries per widget: 2 (two series or two dimensions)
API requests/day ~= 40 * 6 * 24 * 2 ~= 11,520

This is just the dashboard component. Add third-party tooling polling and wallboards to complete the picture.

How to reduce requests (without breaking monitoring)

Increase refresh interval for slow-moving metrics.
Reduce widgets and series per widget; aggregate at the service level.
Consolidate overlapping dashboards and remove unused ones.
Ensure only one tool polls CloudWatch as the source-of-truth (avoid duplicated polling).

Turn it into cost

CloudWatch metrics cost Dashboard pricing

Validation checklist

Measure a real week of metrics API request counts and compare to the model.
Identify “always-on” polling (wallboards and NOC screens) and quantify their refresh intervals.
Confirm whether multiple tools poll the same metrics in parallel.
After changes, validate dashboards still load and alerting still works.