Infracost — Cloud Cost Estimates for Infrastructure as Code

What it is

Infracost is a CLI tool that generates cloud cost estimates from Terraform plans. Before deploying any infrastructure change, you can see exactly how it affects your monthly bill. It supports AWS, Azure, and Google Cloud with pricing data for hundreds of resource types. Infracost integrates with CI/CD pipelines to post cost diffs as pull request comments.

Infracost targets DevOps engineers and platform teams who want cost visibility as part of the infrastructure review process, not as an after-the-fact surprise on the cloud bill.

How it saves time or tokens

Cloud cost surprises typically surface weeks after deployment on the monthly invoice. Infracost shifts cost awareness to the planning stage. A developer proposing a change from t3.medium to r5.2xlarge sees the cost impact immediately in the PR comment. This prevents expensive mistakes and enables cost-informed architecture decisions without waiting for the finance team to flag anomalies.

How to use

1. Install and authenticate:

brew install infracost
infracost auth login

1. Generate a cost breakdown:

cd my-terraform-project
infracost breakdown --path .

1. Compare costs between changes:

infracost diff --path . --compare-to infracost-base.json

Example

Infracost output for a Terraform plan:

Project: my-terraform-project

 Name                          Monthly Qty  Unit   Monthly Cost

 aws_instance.web
   Instance usage (Linux/UNIX, on-demand, t3.medium)  730  hours      $30.37
   root_block_device - Storage (gp3)                   20  GB          $1.60

 aws_rds_instance.db
   Instance usage (on-demand, db.r5.large)            730  hours     $175.20
   Storage (gp2)                                      100  GB         $11.50

 OVERALL TOTAL                                                      $218.67

Related on TokRepo

• AI Tools for DevOps — infrastructure and cloud management tools
• AI Tools for Monitoring — cost monitoring and observability

Common pitfalls

• Infracost estimates are based on list pricing and usage assumptions; actual costs may differ due to reserved instances, savings plans, or usage-based resources
• Some resource types (Lambda invocations, S3 requests) require usage estimates in an Infracost usage file; without them, these costs show as $0
• Free-tier resources still appear with their standard pricing; Infracost does not account for AWS Free Tier eligibility