Calculations from Jira to dashobard

[AJ]

I have created some custom fields for "sizing" product/eng requests. The simple model is S, M, L. 

Small = 1 sprint (2 weeks)

Medium = 2

Large = 3

I am trying to figure out (if possible) how I can run a report in a dashboard/confluence to show that if we get 10 requests this week and each one is a "Small" then that equals 10 sprints of work or effectively 5 months. 

I am open to changing my t-shirt sizing to actual numbers if I have to. 

I am a newbie using Jira calculations so was having a hard time figuring it out. 

[Aron Gombas _Midori_]

Options:

1. If you are ready to use a Number type custom field for the "size", then you can use the SumUp app to make some basic calculations with those (SUM is definitely possible).
2. If you'd rather keep the T-shirt sizing concept, then you can use the Better Excel Plugin with a custom Excel template. The template should export the given custom fields, then use the LOOKUP() function to map those to numeric values and then use SUM() ti calculate the total. See this page on using functions and formulas.