i want sum something using two criteria

[WaqB]

How do sum the data by grade an contract in the example below

example data

Grade Contract Salary
A union 2
A non union 3
B union 4
B non union 5
C union 6
C non union 7

 

[Mike H]

Try this

=SUMPRODUCT((A2:A7="A")*(B2:B7="union")*(C2:C7))

Mike