Chicken egg size: length × breadth by egg size, USDA weight classes, 3D egg models — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/chicken-eggs/  (CC BY 4.0)
Basis: Peer-reviewed measurement of 2,476 eggs from nine genotypes (length, breadth, weight); USDA size classes by weight per dozen
Catalog version: 2026-10-20

Overall (mm): length 56.2, width 42.96, height 42.96
- Measured means: egg-type hens (supermarket eggs) 56.2 × 43.0 mm, 58.3 g; meat-type hens 59.1 × 44.1 mm, 64.6 g; small standard breeds 51.3 × 39.8 mm, 45.4 g. Overall 57.9 × 43.5 mm.
- Breadth / length (shape index) about 0.75; the widest point sits slightly toward the blunt end (modelled with the Hügelschäffer egg curve).
- US sizes are by weight per dozen, not dimensions: Jumbo 30 oz, Extra Large 27, Large 24, Medium 21, Small 18, Peewee 15 (minimums). A US Large egg averages at least 56.7 g, close to the egg-type mean above.
- Holders and incubator trays: size the seat for the breadth (43–44 mm for Large / Extra Large) and let the egg sit blunt end up.

egg  length_mm  breadth_mm  weight_g
egg-type hens (mean)  56.2  42.96  58.34
meat-type hens (mean)  59.05  44.06  64.62
standard breeds (mean)  51.33  39.78  45.4
all 2,476 eggs  57.88  43.52  61.88
USDA Large (min per egg)  None  None  56.7
USDA Extra Large (min per egg)  None  None  63.8
USDA Jumbo (min per egg)  None  None  70.9

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Turkish Journal of Agriculture - Food Science and Technology: Weight and shape-related traits in eggs from different chicken genotypes — web — Publisher's page; dimensions are facts — https://agrifoodscience.com/index.php/TURJAF/article/download/7298/3431/63025
- Eggland's Best: USDA egg size classes (weight per dozen) — web — Publisher's page; dimensions are facts — https://www.egglandsbest.com/faqs/egglands-best-egg-sizes-determined

Free files (CC BY 4.0, Xem Studio; STEP + STL, 4 parts): https://xemstudio.com/files/hardware/chicken-eggs/index.json
API: https://xemstudio.com/api/geometry?object=chicken-eggs