Which lays more eggs, the ISA Brown or the Leghorn?

The ISA Brown typically lays more: 300–350 eggs a year against the Leghorn's 280–320. Strain matters, though — hatchery lines of any breed usually out-lay show lines.

Which starts laying first, the ISA Brown or the Leghorn?

About the same age: 16–18 weeks for the ISA Brown and 16–18 for the Leghorn. Daylight is the wildcard for both — a fall-hatched pullet often waits for lengthening spring days regardless of breed.

Can you keep ISA Browns and Leghorns together?

Yes. Both need the same feed, coop, and run, and mixed-breed backyard flocks are the norm. Size the housing to the more demanding bird: plan on 4 sq ft of coop floor per bird for this pairing, plus run space.

What color eggs do ISA Browns and Leghorns lay?

The ISA Brown lays brown eggs and the Leghorn lays white — keeping both gives you a two-tone basket.

ISA Brown vs Leghorn: Which Chicken Breed Should You Get?

The short answer: the ISA Brown lays more (300–350 eggs a year vs 280–320), and both start laying around the same age (16–18 weeks vs 16–18).

Figures reviewed against hatchery and breed-registry guidance · Last reviewed July 2026

Side by side

	ISA Brown	Leghorn
Eggs per year	≈ 300–350	≈ 280–320
Egg color	brown	white
First egg	16–18 weeks	16–18 weeks
Size class	standard	standard
Coop floor per bird	4 sq ft	4 sq ft

The two commercial-grade layers: brown eggs from the ISA, white from the Leghorn. Both start early and lay hard; egg color, feed thrift, and laying lifespan separate them.

ISA Brown in brief

A commercial hybrid bred purely for egg output — the earliest, heaviest layer most keepers will ever own. The trade-off is a shorter productive life than heritage breeds.

More detail: when do ISA Brown chickens start laying?

Leghorn in brief

The commercial white-egg layer. Leghorns are light, active, economical eaters and among the earliest breeds to lay — but flighty, and rarely broody.

More detail: when do Leghorn chickens start laying?

Which should you pick?

Pick the ISA Brown for brown eggs and the higher first-year count (300–350).

Pick the Leghorn for white eggs, thrifty feed use, and a heritage breed’s longer laying life.

And honestly, most keepers don't have to choose. Both breeds eat the same feed and share a coop happily, so a couple of each is a common answer — use the coop size calculator to size the setup for your total flock, and the first egg calculator to see when each breed will start laying from your chicks' hatch date.

Frequently asked questions

Which lays more eggs, the ISA Brown or the Leghorn?: The ISA Brown typically lays more: 300–350 eggs a year against the Leghorn's 280–320. Strain matters, though — hatchery lines of any breed usually out-lay show lines.
Which starts laying first, the ISA Brown or the Leghorn?: About the same age: 16–18 weeks for the ISA Brown and 16–18 for the Leghorn. Daylight is the wildcard for both — a fall-hatched pullet often waits for lengthening spring days regardless of breed.
Can you keep ISA Browns and Leghorns together?: Yes. Both need the same feed, coop, and run, and mixed-breed backyard flocks are the norm. Size the housing to the more demanding bird: plan on 4 sq ft of coop floor per bird for this pairing, plus run space.
What color eggs do ISA Browns and Leghorns lay?: The ISA Brown lays brown eggs and the Leghorn lays white — keeping both gives you a two-tone basket.

More breed matchups

Sources

First-egg age and egg counts are the consensus of multiple hatchery and breed-registry sources (no extension service tabulates per-breed figures), cross-checked and last reviewed July 2026.

The Livestock Conservancy — Chicken breed profiles