Different Cost Datasets in AWS Cost Explorer

Net unblended, net amortized, blended, amortized, unblended costs

If you have used AWS before, you probably have came across this when using the Cost Explorer, or Cost and Usage Report:

It can get confusing which costs should you use, especially when you are in the business/finance teams within a sizeable company using AWS.

In the following segments, I painted a few scenarios of when each type should be used.

(1) General Analysis

The Net Unblended Costs view is recommended, which will give you total net costs after EDP/PPA discounts are applied (if have).

(2) Indepth Analysis on Your EDP discounts + You have EDP/PPA

To break out the discounts from the original prices, we can use the Unblended Costs view. There is an additional filters under “Charge Type” for the Cross Service Discount, “Enterprise Discount Program Discount”.

(3) You have RI/SP + Want Day to Day Cost Analysis

Net Amortized Cost or Amortized Cost is a good place to start, you can take a look at the differences below when it’s compared to net unblended cost.

Net unblended:

Net amortized:

We notice that the RI/SP costs are evened out, which is a more realistic view of the daily spending.

What about blended?

Blended costs were originally created to support customers who chose to consolidate their billing under a single paying account. Nowadays, these costs are not used frequently due to the way that they are calculated.

Blended costs are calculated by multiplying each account’s service usage against something called a blended rate. A blended rate is the average rate of on-demand usage, as well as Savings Plans- and reservation-related usage, that is consumed by member accounts in an organization for a particular service. Sound complicated? Well, it can get more nuanced, such as in some service-specific examples.

So, unless you have some specific use cases for forecasting based on average rates or something along those lines, I would generally steer away from using the blended cost dataset.

Conclusion

In consulting speak, this scenario analysis doesn’t seem MECE at all. It doesn’t seem to cover all the use cases out there.

The truth is, different companies run their finance and accounting differently and which approach each of us take differs.

My advise is to try it, understand the calculations behind, and go with it. Cheers!