When worn without making a maedare (apron), the length of a rokushaku fundoshi should be equal to the length from one hand to the other hand when both arms are stretched out horizontally plus the length from the center line of the body to one hand the arms are stretched out horizontally (approximately three times the circumference of the waist).
長さの目安は、前垂れを出さない場合、生地の端を持ち、両腕で水平に拡げ、次に、残こり生地の端を持ち、身体中央から更に、片腕で水平に伸ばした長さである。（胴回りの約3倍）