Chick Brooder Size Calculator
A chick brooder size calculator plans space, heat and feed together: 10 chicks at 2 weeks old need 5 square feet of brooder, 90°F of warmth and about a 50-watt heat lamp. Enter your chicks below for the full week-by-week schedule.
Chick Brooder Size & Heat Planner
Planning estimate. Figures vary by breed, strain, climate and management — see the sources cited on this page.
Key facts
- Brooder temperature: 95°F in week 1 (35°C), dropping 5°F a week to 70°F by week 6. Source: Poultry Extension
- Brooder space: 0.5 sq ft per chick in weeks 1–2, 1 sq ft in weeks 3–4, 2 sq ft in weeks 5–6.
- Heat lamp: about 10 W per sq ft of brooder at 70°F room temperature, plus 20% for every 10°F the room is below 70°F.
- Feed by week: about 0.03 lb per chick per day in week 1, 0.05 in week 2, 0.08 in week 4 and 0.12 by week 6.
How the chick brooder size calculator works
Enter the number of chicks, their age in weeks and the room temperature, and the planner works out brooder floor space, the target temperature, the heat-lamp wattage and the daily starter feed. It also prints a week-by-week schedule from week 1 to week 6, so you can see how space and feed grow as the chicks do.
The schedule is the point: chicks quadruple their space need in six weeks, from half a square foot each to two square feet each. Planning the brooder for week 6, not week 1, is what stops you rebuilding the brooder halfway through.
How big should a brooder be for chicks?
Ten chicks need 5 square feet in weeks 1 and 2, 10 square feet in weeks 3 and 4, and 20 square feet by weeks 5 and 6. Twenty chicks need double that — 10, 20 and 40 square feet — so a large batch outgrows a small box fast.
Give chicks a warm end and a cool end, not one even temperature across the whole brooder. Chicks that huddle under the lamp are cold, chicks pressed against the far wall are too hot, and chicks spread evenly across the brooder are just right.
What temperature should a brooder be?
A brooder should be 95°F (35°C) under the lamp in week 1, dropping by 5°F each week — 90°F in week 2, 85°F in week 3, 80°F in week 4, 75°F in week 5 and 70°F in week 6. Measure at chick height, not at the ceiling, and adjust the lamp height or bulb wattage to suit.
Watch the chicks as well as the thermometer, because draughts and room temperature change what the chicks actually feel. A heat lamp of about 10 watts per square foot of brooder at 70°F room temperature is the planning figure, with more watts needed in a colder room.
What this calculator does not do
This planner sizes the brooder and its heat; it does not replace watching the chicks. Pasty butt, cold chicks and overheating are behaviour and health problems, not maths problems, and they need a keeper's eye several times a day in the first week.
It also assumes healthy chicks on starter feed with clean water. Sick, weak or shipped chicks may need extra warmth and a closer watch, and any chick that is not eating or drinking needs attention the same day.
Frequently asked questions
How big should a brooder be for chicks?
10 chicks need 5 sq ft in weeks 1–2, 10 sq ft in weeks 3–4 and 20 sq ft in weeks 5–6. Space per chick is 0.5 sq ft, then 1 sq ft, then 2 sq ft as they grow.
How much space do chicks need in a brooder?
0.5 sq ft per chick in weeks 1–2, 1 sq ft per chick in weeks 3–4 and 2 sq ft per chick in weeks 5–6. Plan the brooder for week 6, not week 1.
Brooder size per chick?
Half a square foot per chick for the first two weeks, one square foot for weeks 3–4 and two square feet for weeks 5–6.
What temperature should a brooder be for week 2 chicks?
90°F (32°C) in week 2, dropping 5°F a week from 95°F in week 1. Measure at chick height and watch the chicks: huddling means cold, spreading to the far wall means too hot.
How many chicks per square foot in a brooder?
Two chicks per square foot in weeks 1–2, one per square foot in weeks 3–4 and one chick per two square feet in weeks 5–6.
The How to Raise Baby Chicks guide covers this topic in more detail. Two related calculators worth checking next are the Brooder Temperature Calculator and Chick Growth Calculator.