Below is a head circumference chart to use in reference with making a headband. The left side of the table is a baby's age in months. The right side of the table is the average head circumference in centimeters for the adjacent age. You want the headband to be a little snug. So measure your headband to be a little smaller than the head circumference.
What exactly is "a little smaller" when making a headband either for a baby or an adult. If I use a 6mm piece of stretch "velvet" elastic to make a headband for a baby, how much smaller should the headband be? It seems like if I made a similar headband with stretch lace, there might be a need for more ease than in using elastics. If I made a headband for an adult, for example, in a five-inch wide stretch elastic, it seems the lace should be cut almost the same size as the head. With tightly woven elastics like a 6-12 mm "velvet" elastic, how "loose" can it be without falling off or causing a headache? Is there any correlation between the width of the elastic or stretch lace and the final size a headband should be? Thank you.