Big Blue Sonic The Hedgehog Youth's Licensed T-Shirt Big Sonic The Hedgehog Blue Color Short Sleeve Licensed- Authentic T-Shirt - Youth's T-Shirt -100% Cotton Color: Blue - BRAND NEW Shirt Specific Dimensions (inches) Size Width Length Small 17" 22" Medium 17" 24" Large 18" 24" X-Large 19" 26" Doubling the width measurement will give you the chest size.