Is this IB Margin calculator correct?

I am trading the popular forex pairs using twice the minimum position that IB can offer. when i calculate the margin exposure in my base currency, they seem to be really off and not equal. I need some more eyes to see if my calculation is correct?
Here is a screenshot of the calculation and also attached the spreadsheet


here is the spreadsheet that i use
http://tiny.cc/IBMarginCalc

Hi guys,

I dont know if I this question is suitable for this thread, but I will try. Because if I dont ask answer is still no.

So I need help with margin formula with multiple trades when Im buying/ selling, just averagng my entry level.

USDCAD
Price l volume l margin
1. buy at 1.3510 0,01 ?
2. buy at 1.3520 0,01
3. buy at 1.3530 0,02
4. buy at 1.3550 0,03
5. buy at 1.3570 0,05

Do you know how to count formula from some weighted average after this move and rising volume. I need to put in my excel.

Thank you