How much flooring do I need for a 20x20 room?

Buy about 440 sq ft: the 400 sq ft floor plus 10% for cuts and waste. With boxes that cover 20 sq ft, that's 22 boxes. Diagonal or herringbone layouts need 15–20% extra instead.

How much paint do I need for a 20x20 room?

With 8 ft ceilings, one door and one window, the walls are about 604 sq ft. Two coats at 350 sq ft per gallon is 3.5 gallons, so buy 4. Painting the ceiling as well brings it to 5.7 gallons.

How many square meters is 20 by 20 feet?

37.16 m². The room is 6.1 m by 6.1 m.

How many sheets of drywall for a 20x20 room?

About 35 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 20x20 Room?

A 20x20 room is 400 square feet (37.2 m²). Flooring with waste, paint, drywall and baseboard for a 20x20 room.

Updated October 12, 2026 · FloorFigures

Short answer

A 20x20 room is 400 square feet (20 × 20), or 37.2 m² and 44.4 square yards. Its perimeter is 80 ft. Flooring with 10% waste comes to about 440 sq ft.

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

Materials for a 20x20 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	400 sq ft	Wall to wall
Flooring to buy	440 sq ft (22 boxes)	10% waste, 20 sq ft boxes
Carpet	54.7 sq yd	12 ft roll, 1 seam
Wall area	604 sq ft	8 ft walls, less a door and a window
Paint, walls	3.5 gal (buy 4)	2 coats, 350 sq ft per gallon
Paint, walls and ceiling	5.7 gal	2 coats
Drywall	35 sheets	4x8 sheets, walls and ceiling, 10% waste
Baseboard	77 ft	Perimeter less a 3 ft door

What a 20x20 room is used for

Rooms this size are usually garages (a two-car garage is commonly 20–24 ft on each side), great rooms, basements or open-plan living areas. A queen bed (60" × 80") takes up about 33 sq ft, or 8% of the floor.

20x20 in other units

Unit	Value
Square feet	400
Square meters	37.16
Square yards	44.44
Square inches	57,600
Acres	0.0092
Dimensions in meters	6.1 × 6.1 m

Rooms close to 20x20

Room	Square feet	Square meters
16x20	320	29.7
18x18	324	30.1
18x20	360	33.4
16x24	384	35.7
18x24	432	40.1
20x22	440	40.9
20x24	480	44.6
22x22	484	45

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 20x20 room?: A 20 by 20 foot room is 400 square feet: 20 × 20 = 400. That's 37.2 square meters or 44.4 square yards.
How much flooring do I need for a 20x20 room?: Buy about 440 sq ft: the 400 sq ft floor plus 10% for cuts and waste. With boxes that cover 20 sq ft, that's 22 boxes. Diagonal or herringbone layouts need 15–20% extra instead.
How much paint do I need for a 20x20 room?: With 8 ft ceilings, one door and one window, the walls are about 604 sq ft. Two coats at 350 sq ft per gallon is 3.5 gallons, so buy 4. Painting the ceiling as well brings it to 5.7 gallons.
How many square meters is 20 by 20 feet?: 37.16 m². The room is 6.1 m by 6.1 m.
How many sheets of drywall for a 20x20 room?: About 35 sheets of 4x8 drywall for the walls and ceiling with 8 ft walls, one door and one window, including 10% waste.