Welcome to Atlassian Community!
It's possible to show this information in Confluence using Jira gadgets.
First, you need to create a filter that contains all tickets that you need to sum and a filter for tickets where you need to see the estimated hours.
On Confluence, you can use the macro Workload Pie Chart. There are many options for the "Statistic Type" that you need to select what fits better for your environment and then you can select between Time Spent, Original estimate and Current estimate.
Please, give it a try and let us know how it goes.
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event