In Excel, I would use SUMIF (limited to one condition column), or the more powerful newer variant SUMIFS (can handle multiple conditions). Basically, sum if something on the same row in another column matches a condition.

There are several other methods that have their places, but SUMIFS and COUNTIFS are my "go to" formulas for almost everything I do.

Pivot tables will also do what you are looking for without writing a formula. But they are harder to get further analysis out of.