AWS for DevOps — Cost Explorer & Budgets

14.2 — Cost Explorer & Budgets

You can’t optimize what you can’t see. Cost Explorer shows where your money goes. Budgets alert you before you overspend.

Cost Explorer

Cost Explorer provides visual cost analysis. Enable it once, and it retains 13 months of data.

# Get last month's cost by service
$ aws ce get-cost-and-usage \
    --time-period Start=2026-03-01,End=2026-03-31 \
    --granularity MONTHLY \
    --metrics BlendedCost \
    --group-by Type=DIMENSION,Key=SERVICE
{
    "ResultsByTime": [{
        "TimePeriod": {"Start": "2026-03-01", "End": "2026-03-31"},
        "Groups": [
            {"Keys": ["Amazon EC2"], "Metrics": {"BlendedCost": {"Amount": "542.30"}}},
            {"Keys": ["Amazon RDS"], "Metrics": {"BlendedCost": {"Amount": "198.50"}}},
            {"Keys": ["Amazon S3"], "Metrics": {"BlendedCost": {"Amount": "45.20"}}},
            {"Keys": ["AWS Lambda"], "Metrics": {"BlendedCost": {"Amount": "12.80"}}}
        ]
    }]
}

# Get daily cost trend
$ aws ce get-cost-and-usage \
    --time-period Start=2026-03-01,End=2026-03-31 \
    --granularity DAILY \
    --metrics BlendedCost

# Get cost by tag (Environment)
$ aws ce get-cost-and-usage \
    --time-period Start=2026-03-01,End=2026-03-31 \
    --granularity MONTHLY \
    --metrics BlendedCost \
    --group-by Type=TAG,Key=Environment

Cost Forecast

# Forecast next month's cost
$ aws ce get-cost-forecast \
    --time-period Start=2026-04-01,End=2026-04-30 \
    --metric BLENDED_COST \
    --granularity MONTHLY
{
    "Total": {
        "Amount": "825.40",
        "Unit": "USD"
    },
    "ForecastResultsByTime": [...]
}

AWS Budgets

Budgets alert you when costs exceed (or are forecasted to exceed) a threshold.

# Create a monthly budget of $1000
$ aws budgets create-budget \
    --account-id 123456789012 \
    --budget '{
      "BudgetName": "monthly-total",
      "BudgetLimit": {"Amount": "1000", "Unit": "USD"},
      "TimeUnit": "MONTHLY",
      "BudgetType": "COST"
    }' \
    --notifications-with-subscribers '[
      {
        "Notification": {
          "NotificationType": "ACTUAL",
          "ComparisonOperator": "GREATER_THAN",
          "Threshold": 80,
          "ThresholdType": "PERCENTAGE"
        },
        "Subscribers": [{
          "SubscriptionType": "EMAIL",
          "Address": "devops@example.com"
        }]
      },
      {
        "Notification": {
          "NotificationType": "FORECASTED",
          "ComparisonOperator": "GREATER_THAN",
          "Threshold": 100,
          "ThresholdType": "PERCENTAGE"
        },
        "Subscribers": [{
          "SubscriptionType": "EMAIL",
          "Address": "devops@example.com"
        }]
      }
    ]'

Recommended Budget Alerts

Budget	Threshold	Notification
Total monthly	80% actual	Email + Slack
Total monthly	100% forecasted	Email + PagerDuty
Per-service (EC2)	90% actual	Email
Per-environment (production)	80% actual	Email
Per-team (tag-based)	80% actual	Team Slack channel

Cost Anomaly Detection

# Create a cost anomaly monitor
$ aws ce create-anomaly-monitor \
    --anomaly-monitor '{
      "MonitorName": "service-monitor",
      "MonitorType": "DIMENSIONAL",
      "MonitorDimension": "SERVICE"
    }'

# Create a subscription for alerts
$ aws ce create-anomaly-subscription \
    --anomaly-subscription '{
      "SubscriptionName": "cost-anomaly-alerts",
      "MonitorArnList": ["arn:aws:ce::123456789012:anomalymonitor/monitor-abc123"],
      "Subscribers": [{"Address": "devops@example.com", "Type": "EMAIL"}],
      "Threshold": 50,
      "Frequency": "IMMEDIATE"
    }'

Common Mistakes

Mistake	Why It Hurts	Fix
No budget alerts	Surprise bill at month end	Set budget at 80% and 100% thresholds
Only total budget	Can’t find which service spiked	Create per-service and per-tag budgets
No forecasted alerts	React too late	Alert when forecast exceeds budget
Not using Cost Anomaly Detection	Miss sudden cost spikes	Enable anomaly detection

Quick Reference

Task	Command
Get cost by service	aws ce get-cost-and-usage --time-period Start=...,End=... --granularity MONTHLY --metrics BlendedCost --group-by Type=DIMENSION,Key=SERVICE
Get cost forecast	aws ce get-cost-forecast --time-period Start=...,End=... --metric BLENDED_COST --granularity MONTHLY
Create budget	aws budgets create-budget --account-id ID --budget '...' --notifications-with-subscribers '...'
List budgets	aws budgets describe-budgets --account-id ID

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