My son is 20 months old (35 inches tall, 27 pounds) and usually wears 2T. I read the reviews and saw that they are a bit small so I bought a size 3t. It fits my son perfectly! The width is perfect but longer in the torso and arms (probably more true to size if your boy is long and narrow in the torso).
Soft Brushed Fleece Crewneck Sweatshirt for π Boys and Girls 4-12 Years - Kid Nation Kids
42 Review
The Good Day Lab Clean Shield: Ultimate Comfort and Breathability in Tagless 4-Way Stretch Polo
43 Review
Boys' Long-Sleeve Disney Star Wars Marvel T-Shirts by Spotted Zebra
46 Review
Van Heusen Sleeve Dress Poplin
42 Review
Waterproof Cozy-Dry Rain/Snow Pants for π§ Kids by JAN & JUL, with Fleece Lining
64 Review
π Fruit of the Loom 6 Pair Cushion Ankle Boys' Clothing: Comfy and Stylish Selection for Active Boys
57 Review
Funny Guy Mugs Tearaway Sweatpants: Playful Boys' Clothing for Fun and Active Days
49 Review
π Boys' Outdoor Climbing Convertible Trousers - Waterproof | Clothing
47 Review