Introducing An AWS Savings Plans Calculator

Lokesh Taneja
4 min readNov 30, 2021

Cloudshim is excited to announce the launch of the AWS Savings Plans calculator. A simple calculator to determine how much Compute or EC2 Savings plan commitment is required for your use case.

To access the AWS Savings Plans Calculator, click here.

AWS Savings Plans are a discount plan that offers significant savings (up to 72%) over On-Demand EC2 compute usage in exchange for a commitment (1-year or 3-year period). Key things to note when considering AWS Savings Plans:

  • If you have existing Reserved Instances (RIs), Savings Plans apply to your usage after RIs are applied.
  • EC2 Savings Plans are applied before Compute Savings Plans.
  • Savings Plans are applied to the purchasing account first, then to other accounts’ usage in a consolidated billing family.
  • Compute Savings Plans have broader applicability and include Fargate and Lambda; these apply from largest to smallest discount in order.
  • Strategize purchasing Savings Plans in an empty account for an organization to benefit highest possible savings across all your EC2 compute usage. To learn more on how Savings Plans are applied, click here.

AWS computes your Savings Plans recommendation in the cost explorer and allows you to toggle through the payment terms, options, and historical look back to determine the best commitment. To best understand and analyze these recommendations, we recommend going through Analyze your Savings Plan Recommendations published by the AWS Well-Architected labs team.

In some cases, there will be No Recommendations for any selection of options. Possible causes could be due to:

  • The average On-Demand spend of the EC2s is less than $0.10/hour
  • The EC2s are not on 100% utilization (i.e., not running 24/7)
  • The EC2s have partial or complete coverage with RIs

In these cases, you can still leverage the flexibility and discounts that Savings Plans offer, but this will require manually calculating the required commitment.

To aid with this calculation, we built the AWS Savings Plans calculator. The calculator will allow you to:

  • Calculate total EC2/Compute Savings Plans commitment for 1-year or 3-year commitments
  • Mix and aggregate calculations for different regions and instance families
  • Specify the quantities and Utilization (On-demand hours) to ensure you do not over-commit
  • Give you a visual breakeven point for your use case

For more info on how to use the calculator and data refresh, please read the FAQ below.

FAQs

What is the source of the pricing data?

We consume the AWS offer file for Cloudshim’s RI/SP commitment manager. We are using the data from the same offer file to map all the instance prices. To read more about the offer file, click here.

How often do you refresh the data?

The data is refreshed in a weekly cycle.

Are there limits to how many users can access the calculator at one time?

The data fetch is being processed by S3 select. The access will be limited to S3 Select limitations. In case you are experiencing any performance issues, please reach out to us via the chat widget.

How do I determine my Utilization?

If you are running your EC2 on 100% On-Demand, then leave the Utilization at 100%. In case you have existing RIs or the instance is on a Start/Shut schedule, you can use this prepopulated link that redirects to the AWS Cost Explorer and filters on your instance type and On-Demand hours breakdown:

For each instance type, your On-demand Utilization will be:

Total usage (Hrs) / (no. of instances * 24 * No. of days)

PS: Adjust the No. of days look back to your desired days

How do I read the breakeven chart?

The breakeven chart shows when your Compute or EC2 SP will pay off for itself. The breakeven point shows the duration of the commitment it takes to pay off the entire savings plan and combines the discount and Utilization. After this day, even if you turn off all your usage, you will not lose any money.

Have more questions?

If you have any questions or issues using the calculator, please don’t hesitate to reach us.

The available methods are:

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