How much flooring do I need for a 18x24 room?

Buy about 475 sq ft: the 432 sq ft floor plus 10% for cuts and waste. With boxes that cover 20 sq ft, that's 24 boxes. Diagonal or herringbone layouts need 15–20% extra instead.

How much paint do I need for a 18x24 room?

With 8 ft ceilings, one door and one window, the walls are about 636 sq ft. Two coats at 350 sq ft per gallon is 3.6 gallons, so buy 4. Painting the ceiling as well brings it to 6.1 gallons.

How many square meters is 18 by 24 feet?

40.13 m². The room is 5.49 m by 7.32 m.

How many sheets of drywall for a 18x24 room?

About 37 sheets of 4x8 drywall for the walls and ceiling with 8 ft walls, one door and one window, including 10% waste.

Room sizes

How Many Square Feet Is a 18x24 Room?

A 18x24 room is 432 square feet (40.1 m²). Flooring with waste, paint, drywall and baseboard for a 18x24 room.

Updated October 12, 2026 · FloorFigures

Short answer

A 18x24 room is 432 square feet (18 × 24), or 40.1 m² and 48 square yards. Its perimeter is 84 ft. Flooring with 10% waste comes to about 475 sq ft.

Drawn to scale. Each grid square is 1 ft × 1 ft.

Materials for a 18x24 room

Estimates for a plain rectangular room with 8 ft ceilings, one door and one window. Adjust for your own room with the flooring, paint and drywall calculators.

Item	Quantity	Assumes
Floor area	432 sq ft	Wall to wall
Flooring to buy	475 sq ft (24 boxes)	10% waste, 20 sq ft boxes
Carpet	49.3 sq yd	12 ft roll, 1 seam
Wall area	636 sq ft	8 ft walls, less a door and a window
Paint, walls	3.6 gal (buy 4)	2 coats, 350 sq ft per gallon
Paint, walls and ceiling	6.1 gal	2 coats
Drywall	37 sheets	4x8 sheets, walls and ceiling, 10% waste
Baseboard	81 ft	Perimeter less a 3 ft door

What a 18x24 room is used for

Rooms this size are usually great rooms, open-plan living areas, basements or garages. A queen bed (60" × 80") takes up about 33 sq ft, or 8% of the floor.

18x24 in other units

Unit	Value
Square feet	432
Square meters	40.13
Square yards	48
Square inches	62,208
Acres	0.0099
Dimensions in meters	5.49 × 7.32 m

Rooms close to 18x24

Room	Square feet	Square meters
18x18	324	30.1
18x20	360	33.4
16x24	384	35.7
20x20	400	37.2
20x22	440	40.9
20x24	480	44.6
22x22	484	45
22x24	528	49.1

Room not a simple rectangle? Use the square footage calculator for L-shapes and angled walls, or split it into rectangles.

Questions

How many square feet is a 18x24 room?: A 18 by 24 foot room is 432 square feet: 18 × 24 = 432. That's 40.1 square meters or 48 square yards.
How much flooring do I need for a 18x24 room?: Buy about 475 sq ft: the 432 sq ft floor plus 10% for cuts and waste. With boxes that cover 20 sq ft, that's 24 boxes. Diagonal or herringbone layouts need 15–20% extra instead.
How much paint do I need for a 18x24 room?: With 8 ft ceilings, one door and one window, the walls are about 636 sq ft. Two coats at 350 sq ft per gallon is 3.6 gallons, so buy 4. Painting the ceiling as well brings it to 6.1 gallons.
How many square meters is 18 by 24 feet?: 40.13 m². The room is 5.49 m by 7.32 m.
How many sheets of drywall for a 18x24 room?: About 37 sheets of 4x8 drywall for the walls and ceiling with 8 ft walls, one door and one window, including 10% waste.