I am a newbie needing this info so I can use the Fargate cost calculator to see how much savings we would get by migrating from ECS.
Fargate cost calculator is here: fargate cost calculator
I have 18 instances running, 5 c5.large, 8 t2.micro, 3 t2.medium, 2 t3.medium. I just have no clue where on the console to click for this info after clicking through to cost explorer and main console page.
If you are using task in EC2 launching type, I don't think there is any console UI/page available in cluster level. Normally, we just calculate manually based on instance type. Here is the details of each instance.
I assume your question is about Fargate lanching type. As part of task creation, you need to specify total cpu and memory for the task. The actual usage might not be the same, however, you can still know average usage by checking Metrics page in ECS Cluster -> Tasks. The values is percentage of actual usage over maximum value. The same is available in cloudwatch ECS metrics as well.
When you register a task definition, you can specify the total cpu and memory used for the task. This is separate from the cpu and memory values at the container definition level. If using the EC2 launch type, these fields are optional. If using the Fargate launch type, these fields are required and there are specific values for both cpu and memory that are supported.