how is the size calculated in Instance List

Hello,

I'm confused about the object size that is shown on Instance List windows of ANTS Memory Profiler.

I have the following entries on the list with their respective size.

Value => Size(byte)
"" => 26
"A" => 28

I know that every char is 2byte. (which can be proofed from the above table)
but don't know what is the remaining memory(26byte) used for.

I think this size includes the string reference too, but what I know is its only 4byte(in x86).

Thanks from now for your answers.
Best Regards
Yucel