Bicycle Mechanics - How do you measure a BB spindle length, when the ends are threaded?

So i'm looking at fixing up my old ten speed. i want to get a new crankset, but i want to reuse the bottom bracket. one of the cranksets i'm looking at says it's best used with BB spindles between a certain length range. i looked on Sheldon Brown (BB size database (http://www.sheldonbrown.com/bbsize.html)) and found it overwhelming, especially since i don't know the make/model of the BB and i haven't taken the whole thing apart yet. This graphic (http://www.sheldonbrown.com/harris/images/ta-bb-axles.gif) makes sense, but my BB has threads that extend beyond the square taper, like the one pictured here (http://i.ebayimg.com/00/$%28KGrHqR,!jIE1NRr,kN!BN,BMq%299ug~~_35.JPG). So would i measure the distance from end to end to get the proper dimension, or would i measure from the end of the square tapers?

i hope this makes sense. Thanks in advance for your help.

for those funky BBs, you don't measure the threaded portions.

You have what is known as a "nutted spindle". You measure from the base of each threaded stub, ignoring the threaded portion. That will give you the same measurement as the required bolted spindle.

Thanks, ya'll.