Effective Savings Rate

1. Determine Original Cost: Gather data on the total amount you would have spent on AWS services without utilizing any cost-saving mechanisms like RIs or Savings Plans. This is your original cost, calculated based on On-Demand prices for the same services and usage.

2. Calculate Net Savings: Subtract any additional costs or adjustments from the total savings. This gives you the net amount saved through cost-saving measures.

3. Calculate Effective Savings Rate (ESR): Divide the net savings by the original cost and multiply by 100 to get the percentage.

Mathematically, the effective savings rate (ESR) can be represented as:

Here's the modified example calculation:

Let's say your original cost, calculated using On-Demand prices for the same services and usage, was $15,000. Your total actual expenditure on AWS services for a month was $10,000. Let's assume there were additional costs such as data transfer fees, amounting to $1,000. Thus, your net savings would be $15,000 - $10,000 - $1,000 = $4,000.

So, your effective savings rate would be approximately 26.67%.

This adjustment incorporates any additional costs or adjustments into the calculation of net savings, providing a more accurate representation of the overall savings achieved.