aws-cost-estimator

title: "Aws Cost Estimator" sidebar_label: "Aws Cost Estimator" description: "Estimate monthly costs for AWS resources using the AWS Pricing API. Parses CloudFormation templates to identify resources, service types, and regions, then looks up real AWS retail pricing. Produces a per-resource cost breakdown with monthly totals. Use during template generation or when user asks about costs."

Aws Cost Estimator

Estimate monthly costs for AWS resources using the AWS Pricing API. Parses CloudFormation templates to identify resources, service types, and regions, then looks up real AWS retail pricing. Produces a per-resource cost breakdown with monthly totals. Use during template generation or when user asks about costs.

Details

Property	Value
Skill Directory	`.github/skills/aws-cost-estimator/`
Phase	General
User Invocable	✅ Yes
Usage	`/aws-cost-estimator CloudFormation template JSON/YAML or list of AWS resources with instance types and region`

Documentation

AWS Cost Estimator

Estimate monthly costs for AWS resources using the AWS Pricing API — a REST API that returns real AWS retail pricing data.

When to Use

During CloudFormation template generation to show cost estimates before deployment
When user asks "how much will this cost?" or "estimate costs"
To compare cost of different instance types or service tiers
To validate budget constraints before deployment

API Reference

Endpoint: https://pricing.us-east-1.amazonaws.com/offers/v1.0/aws/{SERVICE}/current/index.json

Alternative (Bulk Price List API):

GET https://pricing.us-east-1.amazonaws.com/offers/v1.0/aws/AmazonEC2/current/{region}/index.json

Key facts:

No authentication required for public pricing pages
Prices are in USD by default
Use the AWS Pricing Calculator for complex scenarios: https://calculator.aws/
Always note the retrieval date in estimates

Procedure

1. Parse CloudFormation Template Resources

Extract from the CloudFormation template:

Resource type (AWS::EC2::Instance, AWS::RDS::DBInstance, etc.)
Instance/class size (e.g., t3.micro, db.t3.medium)
Region (from template parameter or default)
Storage sizes and types
Any quantity-affecting properties

2. Map Resource Types to Pricing

Use the AWS Pricing API or well-known current rates for common services.

Query pattern using AWS CLI:

# Get pricing for EC2 instances
aws pricing get-products \
  --service-code AmazonEC2 \
  --filters \
    "Type=TERM_MATCH,Field=instanceType,Value=t3.micro" \
    "Type=TERM_MATCH,Field=operatingSystem,Value=Linux" \
    "Type=TERM_MATCH,Field=location,Value=US East (N. Virginia)" \
    "Type=TERM_MATCH,Field=tenancy,Value=Shared" \
    "Type=TERM_MATCH,Field=preInstalledSw,Value=NA" \
    "Type=TERM_MATCH,Field=capacityStatus,Value=Used" \
  --region us-east-1 \
  --query 'PriceList[0]' --output text | python3 -c "
import sys, json
data = json.loads(sys.stdin.read())
for term in data['terms']['OnDemand'].values():
    for price_dim in term['priceDimensions'].values():
        print(f\"{price_dim['description']}: \${price_dim['pricePerUnit']['USD']}/hr\")
"

Resource Type Mapping

EC2 Instances (`AWS::EC2::Instance`)

Service code: AmazonEC2

CloudFormation Property	Pricing Filter
`Properties.InstanceType`	`instanceType`
`Properties.ImageId` (OS detection)	`operatingSystem`: Linux or Windows

Unit: Per hour → multiply by 730 for monthly estimate.

Common instance pricing (us-east-1, Linux, On-Demand):

Instance	vCPU	RAM	Est. $/month
t3.micro	2	1 GB	~$7.59
t3.small	2	2 GB	~$15.18
t3.medium	2	4 GB	~$30.37
t3.large	2	8 GB	~$60.74
m6i.large	2	8 GB	~$69.35
c6i.large	2	4 GB	~$61.20

EBS Volumes (`AWS::EC2::Volume`)

Service code: AmazonEC2

Volume Type	CloudFormation `VolumeType`	Approximate Cost
gp3	`gp3`	~$0.08/GB/month
gp2	`gp2`	~$0.10/GB/month
io1	`io1`	~$0.125/GB/month + $0.065/IOPS/month
st1	`st1`	~$0.045/GB/month

S3 Buckets (`AWS::S3::Bucket`)

Service code: AmazonS3

Standard storage: ~$0.023/GB/month
Intelligent-Tiering (frequent): ~$0.023/GB/month
Standard-IA: ~$0.0125/GB/month
Glacier Instant: ~$0.004/GB/month
PUT/POST requests: ~$0.005/1,000 requests
GET requests: ~$0.0004/1,000 requests

Note: No fixed monthly cost — estimate based on expected data volume.

RDS Instances (`AWS::RDS::DBInstance`)

Service code: AmazonRDS

DB Instance Class	Engine	Est. $/month (Multi-AZ)
db.t3.micro	MySQL/PostgreSQL	~$28 (Multi-AZ ~$57)
db.t3.medium	MySQL/PostgreSQL	~$57 (Multi-AZ ~$115)
db.m6g.large	MySQL/PostgreSQL	~$138 (Multi-AZ ~$277)
db.r6g.large	MySQL/PostgreSQL	~$182 (Multi-AZ ~$365)

Plus: Storage at ~$0.115/GB/month (gp2) or ~$0.115/GB/month (gp3 base)

Lambda Functions (`AWS::Lambda::Function`)

Service code: AWSLambda

Consumption plan pricing:

First 1M requests/month: FREE
Additional requests: $0.20 per 1M requests
First 400,000 GB-seconds/month: FREE
Additional GB-seconds: $0.0000166667 per GB-second

Example (128 MB, 500ms avg, 1M invocations/month):

Compute: 1M × 0.5s × 0.125 GB × $0.0000166667 = ~$1.04
Requests: $0.20
Total: ~$1.24/month (first 1M invocations included)

DynamoDB Tables (`AWS::DynamoDB::Table`)

Service code: AmazonDynamoDB

On-Demand: $1.25 per million write request units, $0.25 per million read request units
Provisioned: $0.00065/WCU/hour, $0.00013/RCU/hour
Storage: $0.25/GB/month
PITR: $0.20/GB/month

ECS/Fargate Tasks (`AWS::ECS::TaskDefinition`)

Service code: AmazonECS

vCPU: $0.04048/vCPU/hour
Memory: $0.004445/GB/hour

Example (0.5 vCPU, 1 GB, running 730 hours/month):

vCPU: 0.5 × $0.04048 × 730 = ~$14.78
Memory: 1 × $0.004445 × 730 = ~$3.24
Total: ~$18.02/month

EKS Clusters (`AWS::EKS::Cluster`)

Control plane: $0.10/hour = ~$73/month (fixed)
Worker nodes (EC2): priced as EC2 instances separately

Secrets Manager (`AWS::SecretsManager::Secret`)

$0.40/secret/month
$0.05 per 10,000 API calls

CloudWatch Logs

Ingestion: $0.50/GB
Storage: $0.03/GB/month
Insights queries: $0.005/GB scanned

3. Calculate Monthly Costs

Apply the correct multiplier:

Unit	Monthly Multiplier	Notes
Per hour	× 730	365 days × 24 hours ÷ 12 months
Per GB/month	× estimated GB	Use actual or default estimate
Per month	× 1	Already monthly
Per request	× estimated volume	Estimate based on workload

4. Handle Free Tier

Note any AWS Free Tier allowances (first 12 months or always free):

Service	Free Tier
Lambda	1M requests + 400K GB-s/month (always free)
DynamoDB	25 GB storage + 25 WCU + 25 RCU (always free)
S3	5 GB Standard storage (12 months)
EC2	750 hours t2.micro/t3.micro (12 months)
RDS	750 hours db.t2.micro/db.t3.micro (12 months)
CloudWatch	10 custom metrics + 5 GB logs (always free)

5. Present Cost Estimate

Format the output as a clear cost breakdown:

### 💰 Estimated Monthly Cost

| # | Resource | Type | SKU/Tier | Est. Monthly |
|---|----------|------|----------|-------------|
| 1 | MyWebServer | EC2 Instance | t3.medium (Linux) | $30.37 |
| 2 | MyWebServer OS Disk | EBS Volume | 20 GB gp3 | $1.60 |
| 3 | MyDatabase | RDS PostgreSQL | db.t3.medium Multi-AZ | $115.00 |
| 4 | MyDatabase Storage | RDS Storage | 100 GB gp3 | $11.50 |
| 5 | MyBucket | S3 Storage | Standard ~50 GB | $1.15 |
| 6 | MyFunction | Lambda | ~1M invocations | $0.20 |
| | | | **Total** | **$159.82/mo** |

**Notes:**
- Prices are AWS retail (pay-as-you-go) in USD for us-east-1
- Actual costs may vary with Reserved Instances, Savings Plans, or enterprise agreements
- Data transfer costs not included (first 100 GB/month outbound: $0.09/GB)
- Estimates based on 24/7 operation (730 hours/month)
- Prices current as of 2026-04-15 — verify at https://calculator.aws/

**Cost Optimization Opportunities:**
- 💡 EC2 1-Year Reserved Instance: ~40% savings on compute
- 💡 EC2 3-Year Reserved Instance: ~60% savings on compute
- 💡 RDS Reserved Instance (1-year): ~40% savings on database
- 💡 Use Savings Plans for flexible commitment discounts

6. Save Cost Estimate

Save the estimate to deployment artifacts:

File: .aws/deployments/{deployment-id}/cost-estimate.json

{
  "estimatedAt": "2026-04-15T00:00:00Z",
  "currency": "USD",
  "region": "us-east-1",
  "monthlyTotal": 159.82,
  "resources": [
    {
      "name": "MyWebServer",
      "type": "AWS::EC2::Instance",
      "sku": "t3.medium",
      "unitPrice": 0.0416,
      "unitOfMeasure": "1 Hour",
      "monthlyEstimate": 30.37
    }
  ],
  "notes": [
    "Retail pay-as-you-go pricing",
    "Data transfer not included"
  ],
  "source": "AWS Pricing API",
  "sourceUrl": "https://pricing.us-east-1.amazonaws.com"
}

Error Handling

If a price cannot be determined:

Show ❓ Price not found with the resource type and instance size
Link to the AWS Pricing Calculator: https://calculator.aws/
Never fabricate a price — show Unknown and provide the manual lookup URL

If the API is unreachable:

Fall back to a note: "Cost estimation unavailable — verify at https://calculator.aws/"
Use the well-known rates table above for common resource types as a fallback estimate

Constraints

DO NOT fabricate or guess prices — use the pricing table above or query the API
DO NOT use hardcoded prices without noting they may be outdated
ALWAYS show the pricing date so users know how current the estimate is
ALWAYS note that actual costs may differ from retail pricing (Reserved Instances, Savings Plans, EDP)
ALWAYS note that data transfer costs are not included in the estimate

Aws Cost Estimator

Details​

Documentation​

AWS Cost Estimator

When to Use​

API Reference​

Procedure​

1. Parse CloudFormation Template Resources​

2. Map Resource Types to Pricing​

Resource Type Mapping​

EC2 Instances (AWS::EC2::Instance)​

EBS Volumes (AWS::EC2::Volume)​

S3 Buckets (AWS::S3::Bucket)​

RDS Instances (AWS::RDS::DBInstance)​

Lambda Functions (AWS::Lambda::Function)​

DynamoDB Tables (AWS::DynamoDB::Table)​

ECS/Fargate Tasks (AWS::ECS::TaskDefinition)​

EKS Clusters (AWS::EKS::Cluster)​

Secrets Manager (AWS::SecretsManager::Secret)​

CloudWatch Logs​

3. Calculate Monthly Costs​

4. Handle Free Tier​

5. Present Cost Estimate​

6. Save Cost Estimate​

Error Handling​

Constraints​

References​