As different bobbins are wound differently, I don't see how you could tell how much is there or how much you will use. I have a Viking, and when I know my bobbin is getting low, I check it between each color, and change it if it looks low. May not help, but thats my story and I'm sticking to it!!! Hahaha!

Claude, the free program from Tajima, Pulse micro, will tell you how much of each top colour, and how much bobbin thread the design uses. Now, how you tell how much thread your bobbin holds, I'm not sure. My 'bobbin fill' is very thin thread, so many more feet. Regular embroidery thread would be less, like for FSL. My cats were helping me measure my spool of purple, there were about 100 feet unstrung and wound all over the house the other day! Hee hee hee, hugs, Marji

Dear marji, thank you very much, I use prewound bobbins, my machine prefer, you know, those machines are as children! and I know exactly le lengtn of thread in a bobbin, it is written on the box, I do not need a cat, I have 3 cats, I love them, and I understand what you say!!! Cna you explain to me where I can obtain for download the software tajima pulsemicro

Claude, here is the link for the free download of the Tajima software. It's in English, but it should not be too hard to figure out. If you have any questions about it, just ask, and I'll try to help. Hugs, Marji