Adding the results of Nested If statements together

First off Thank You for your help. I love writing these equations... especially when they work. Although sometimes I lose my place and find myself writing equations to fix problems in other equations and can hardly remember where I started. That's where I'm at today. So I completely scrapped my old form and all of its equations and re-wrote everything from the beggining as a project to do over the holidays.

I've written the following (functional) IF statement for an online software program I use to do customer quotes called GoFormz. GoFormz allows me to create forms with calculation fields to simplify the form.

My question is how do I modify the following statement so that it will add other IF statements to create a one total. This statement looks at the number in the first cell [H1#Size1] and makes sure it meets the values of [FiltTypeH1]=16.1 or 20.1 or 25.1, and if it is TRUE it returns the number in [H1#Size1] otherwise Zero. This works, but I need to repeat this equation in it's entirity for cells [H1#Size2] and [H1#Size3]. And then again 15 more times for cells [H2#Size1], [H2#Size2], [H2#Size3] the whole way to [H6#Size3]. So this could be a very long statement. I know I could create separate statements for each argument and then another statement that would add them all together. I would just really love it if I could get this into one statement to do it all. Plus it would be a lot neater. Oh, I forgot to mention that I have to do the same thing for 3 other value 16.2, 20.2, 25.2... you get it... it would create 55 separate equations. Big mess.

Note: [FiltTypeH1] is a drop down option with different text options that have the following numerical values of 16.1 or 20.1 or 25.1. The information is not in a table, but rather 18 separate cells on a form.

=IF([FiltTypeH1]=16.1, [H1#Size1], IF([FiltTypeH1]=20.1, [H1#Size1], IF([FiltTypeH1]=25.1, [H1#Size1], IF([FiltTypeH1]=10.1, [H1#Size1], 0)))) - this works.

but I have to add it to this portion

=IF([FiltTypeH1]=16.1, [H1#Size2], IF([FiltTypeH1]=20.1, [H1#Size2], IF([FiltTypeH1]=25.1, [H1#Size2], IF([FiltTypeH1]=10.1, [H1#Size2], 0))))

and then add it to this portion

=IF([FiltTypeH1]=16.1, [H1#Size3], IF([FiltTypeH1]=20.1, [H1#Size3], IF([FiltTypeH1]=25.1, [H1#Size3], IF([FiltTypeH1]=10.1, [H1#Size3], 0))))

Thank you and Happy New Year!
Eric


GoFormz has the following Calculation and Logic fields (http://calculations.goformz.com/docs/and) but includes

LOGIC FUNCTIONS
If
And
Or

MATH FUNCTIONS
Sum
Round
Ceiling
Floor
Average
Min
Max
Count
Count If
Vlookup