# Chicken Coop Size Calculator

URL: https://speedycalculator.com/calculators/construction/chicken-coop/
Last updated: 2026-10-25

> The chicken coop size calculator works out the indoor coop floor area, outdoor run area, roost length and number of nest boxes for a flock of standard-size hens and bantams.

## Inputs

- Standard-size hens
- Bantams

## Results

- Coop floor area
- Square coop side
- Run area
- Roost length
- Nest boxes

## Formula

```
Coop = 4 ft² × standard + 2 ft² × bantam
Run = 10 ft² × standard + 4 ft² × bantam
Roost = 10 in × standard + 6 in × bantam
Nest boxes = ceil(hens ÷ 4)
```

## Explanation

Crowded chickens are stressed, peck each other and get sick, so poultry extension services recommend minimum space per bird. Bantams (miniature breeds) need about half the space of standard hens. These are minimums – free-ranging birds can manage with less run, and birds confined all winter need more coop.

### How to use the Chicken Coop Size Calculator

- **Standard-size hens**
- **Bantams**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the number of standard-size hens and bantams. The calculator adds up the space each needs inside and in the run, the length of perch and the nest boxes, and suggests a square coop size.

### Tips for an accurate estimate

- Take measurements at floor level and at the ceiling – walls and rooms are often slightly out of square.
- Use the manufacturer's coverage, spacing and installation data when it differs from the typical values here.
- Keep a little extra of every finish material for touch-ups and repairs later.
- Check local building codes and permits before structural, electrical, plumbing or gas work.

### Common mistakes to avoid

- Sizing heating or cooling equipment by area alone when insulation, windows and climate make a big difference.
- Buying too little paint, stain or flooring and ending up with mismatched batches.
- Overlooking the extra material for steps, railings, gables and trim.

### Inputs explained

FieldWhat to enterStandard-size hensA numberBantamsA number

### What each result means

- **Coop floor area** = (4×[Standard-size hens] + 2×[Bantams])×0.09290304
- **Square coop side** = sqrt([Coop floor area])
- **Run area** = (10×[Standard-size hens] + 4×[Bantams])×0.09290304
- **Roost length** = (10×[Standard-size hens] + 6×[Bantams])×0.0254
- **Nest boxes** = ceil(([Standard-size hens] + [Bantams])÷4 - 0.000001)

### Example values

How the main result changes when **Standard-size hens** changes and everything else stays at the example values above:

Standard-size hensCoop floor area (ft²)3124.5186247.5309361248

## Worked example

Inputs — Standard-size hens: 6; Bantams: 0.

Results — **Coop floor area = 24 ft²**; Square coop side = 4.9 ft; Run area = 60 ft²; Roost length = 5 ft; Nest boxes = 2.

## FAQ

**How big should a coop be for 6 chickens?**
At least 24 ft² inside (e.g. 5 × 5 ft) plus a 60 ft² run.

**How many nest boxes do hens need?**
One box for every 4–5 hens; they will share.

**How much roost space per chicken?**
8–10 in per standard hen and about 6 in per bantam.

**What formula does the Chicken Coop Size Calculator use?**
Coop = 4 ft² × standard + 2 ft² × bantam.


## Sources

- [University of Maryland Extension – Raising backyard chickens](https://extension.umd.edu/)