Discrepancy in VM Usage on GCP Billing

[RafaCarva]

I have been analyzing the costs of my project on GCP, and I encountered a question regarding some SKU costs. On August 1, 2024, I had two VMs running. One was running for 1 hour and 15 minutes, and the other for just 10 minutes(I've confirmed that by using metrics explorer). What I am struggling to understand is that, when filtering by August 1, 2024, the billing report shows a usage of "44,47 hour" for the SKU "E2 instance Core running in São Paulo". Additionally, other SKUs have different usages.
What calculation is being used to arrive at this value?

[francislouie · Accepted solution]

Hi @RafaCarva,

Welcome to Google Cloud Community!

       The calculation on a monthly or daily basis depends on several factors, including the number of instances, total uptime, instance type, and region you are having. To avoid confusion, you can use the Google Cloud Platform Pricing Calculator. This feature will provide you with a precise estimate of cost and usage. In relation to pricing, you can further check in this documentation about Compute Engine Pricing and SKUs Pricing .

 Based on Google Cloud Calculator, here is the formula on getting estimated cost:

• Predefined instance type

"Number of instance x Usage amount x List price  = estimated cost"

• Custom instance Type

"Number of instance x Usage amount x Number of core x Number of Memory x List price  = estimated cost"

Please take note that the tool estimates based on assumptions that you provide. These estimates may not accurately reflect the final costs on your monthly Google Cloud bill.

To calculate the usage of hours in the billing report,  use this formula:

"Cost / SKUs Price per hour = usage hours"

Example: 

Cost = 0.30$ 

SKUs (E2 instance core running in Sao Paulo) = 0.0346242 USD per hour

0.30$ / 0.0346242$ per hour = 8.66 usage hours 

You can also check the pricing tiers of SKUs in this documentation.

If you have any other questions and specific concerns when it comes to Billing, you can reach out to our Cloud Billing support directly.

I hope the above information is helpful.