How Many Square Feet Is a 9x12 Room?
A 9 ft × 12 ft room equals 108 square feet. Use the calculator below to double-check or customize with waste and cost.
Last updated:Tip: If you only have the diameter, divide by 2 to get the radius.
L-shape = two rectangles sharing a corner.
Add one row per rectangle and we'll sum them.
Key Measurements for a 9x12 Room
| Metric | Value |
|---|---|
| Floor area | 108 sq ft |
| Floor area (m²) | 10.03 m² |
| Floor area (sq yd) | 12.00 sq yd |
| Perimeter | 42 ft |
| Wall area (8 ft ceiling) | 336 sq ft |
| Wall area (9 ft ceiling) | 378 sq ft |
| Wall area (10 ft ceiling) | 420 sq ft |
Common Uses for a 9x12 Space
- child's bedroom
- small guest room
At 108 sq ft, this falls in the small category — typical for bedrooms, offices, or utility rooms.
How Much Flooring Will You Need?
For a 9' × 12' room, buy enough flooring to cover 108 sq ft plus a waste allowance:
| Flooring Type | Waste % | Buy This Much |
|---|---|---|
| Laminate / LVP (plank) | 10% | 119 sq ft |
| Hardwood | 10% | 119 sq ft |
| Ceramic tile (straight) | 10% | 119 sq ft |
| Ceramic tile (diagonal) | 15% | 125 sq ft |
| Carpet | 10% | 119 sq ft (14 sq yd) |
Need an exact estimate? Use our Flooring Calculator for plank count, or the Tile Calculator for boxes of tile.
How Much Paint for a 9x12 Room?
With 8 ft ceilings you'll paint about 336 sq ft of wall. A gallon covers ~350 sq ft, so you'll need 1 gallon per coat. Plan on two coats for a color change.
Detailed breakdown on our Paint Calculator.
Is a 9x12 Room Big?
This is a small room, typical of a child's bedroom or home office. It meets the minimum for a "legal bedroom" in most municipalities (at least 70 sq ft of floor area with one horizontal dimension of 7 ft).
How Much Does It Cost to Build a 9x12 Room?
At typical US rates of $150–$300 per sq ft for new construction, a 9x12 addition would cost roughly $16,200–$32,400. For remodels:
- Basic flooring replacement: $324–$1,080
- Mid-range remodel: $5,400–$10,800
- Full gut renovation: $10,800–$27,000
Refine with our Cost per Square Foot Calculator.
Frequently Asked Questions
How many square feet is 9x12?
9 × 12 = 108 square feet.
How many square meters is 9x12?
10.03 m².
How many tiles will fit in a 9x12 room?
Depends on tile size. 12"×12" tiles = 119 tiles (with 10% waste). See our Tile Calculator for 6", 18", and 24" sizes.
How much carpet do I need for a 9x12 room?
12.00 sq yd minimum, or 13.20 sq yd with 10% waste for cuts and seams.