A kids' BJJ Gi should fit like athletic tailoring: snug
enough to prevent opponents from easily grabbing fabric, but loose enough to
allow full mobility. Sleeves and pant legs must reach just above the ankle and
wrist bones, while the jacket should extend down to cover the hips.

 Key Fit Areas

• Sleeves - Should rest right at the wrist bone or within 2 cm of it. If they are too long, they can snag fingers or get in the way of grips.
• Pant Legs: Should reach just above the ankle bone. Excessively long pants can cause your child to trip during movement.
• Jacket & Skirt: The jacket should close snugly across the chest and extend down over the hips to cover the glutes.
• Shoulders & Armpits: The shoulders shouldn't feel restricted when lifting their arms, but there shouldn't be an excessive amount of loose, baggy material bunched up under the armpits.

 Considerations for Growth

Children grow rapidly, but sizing up too much is a safety hazard.

• Training & Fit: If you want some room to grow, pick a size that is slightly on the roomier side but still within the safe range. Many kids' Gi’s are cut with extra room to allow for this.
• Competition Fit: If your child is competing, the Gi must fit precisely. Overly large Gi’s will fail strict uniform inspections.
• Shrinkage: Many 100% cotton Gi’s shrink 5% to 10% on their first wash, especially if washed in warm water or placed in the dryer.

 Sizing Systems

Unlike adult Gi’s (which use A0-A5 sizing), youth Gi’s
typically use an M-series (or C/Y sizes), which are based on age,
height, and weight.

• M0000 to M000: Ages 3 to 6
• M0 to M2: Ages 6 to 10
• M3 to M4: Ages 11 to 14

 Always prioritize your child's height and weight over their age when looking at any sizing chart