Lost the version I made for wearing below my bike helmet.
Used sockyarn held doubled.
CO 88 stitches, worked short rows until 20 stitches unworked on each side.

Weighed finished headband - used app. 25 gramms of sockyarn held doubled. Fits well, my head (59 cm)and the smaller heads (56 cm) of other family members as well.

Will make more, using tiny sockyarn scraps..