Where do you get Google Bigquery usage info (mainly for processed data)
Post GCP Console Redesign Answer
The GCP console was redesigned and now the other answer here no longer applies, but it is still possible to view your usage by going to IAM & Admin -> Quotas.
What you're looking for is "Big Query API: Query usage per day". It doesn't seem possible to view your usage over 30 days unfortunately, but you can see your current usage (per day) and your peak usage over the past 7 days. You can also set a daily quota. If you're just working infrequently or doing a lot in one day, you can set a quota to 1 TiB and prevent yourself from blowing your whole allocation in one day.
You can try sending feedback about these limitations, like I did, by clicking the question mark at the top right and then send feedback.
From the Google Cloud Console overview page for your project, click on the "details" section on the top-right, next to the charge estimate :
You'll get an estimate of the charges for the current month for each service and item in the service, including Big Query analysis :
If you want to track this usage, you can also export the data into CSV every day by going in the Billing settings and enable the usage export feature. Do not worry about the fact that it only mentions Compute Engine, it actually works for other services also.
You can also access directly the billing history by clicking on the billing account link :
You will get a detailed bill with the usage info :