SUMPRODUCT formula help

Hi Colin,

Thanks for the help!

I have attached the document to this message. So what I am trying to do is create a formula that multiplies entries in column B by column D and then Subtotal the results. Cell D24 does this with the SUMPRODUCT formula, but when I try to filter results in column C (show only the 'a' or 'b' entries), the result in D24 does not adjust to reflect only the visible entries. Please let me know how I can change that!

Thanks,

Matt