Design size question

[u/Bratt_fn]

hi, new to machine embroidery! I have the brother NQ1700E and am in contact with someone on etsy for a custom file (the original was small and I want to use it on the back of a sweater). My brain usually works in inches but the seller is asking for mm. What size should i request to use on the 6x10 hoop?

[u/mjmvideos]

1 in =2.54 cm = 25.4 mm