Room size · 30 × 40

A 30×40 room is 1200 square feet

That’s 133.33 square yards or 111.48 square meters — also written 40×30. The room below is drawn to scale, furniture and all, so the number has something to stand next to.

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Drawn to scale. Grid squares are 5 feet. Shown: car, workbench.

Area 1200 ft²
133.33 sq yd
111.48 m²
Wall area 1120 ft² at 8-ft ceilings
Paint 7 gal 2 coats at 350 ft²/gal
Flooring 59 boxes 22.5 ft²/box, 10% waste

What a 30×40 building actually holds

At this scale the grid above steps to 5-foot squares and the question changes from “does it fit” to “how much stays open.” The facts give the honest version: vehicles and a workshop wall in place, and the open floor measured after them.

Two cars park side by side — each is a typical mid-size sedan (about 15 ft 7 in long) — with 90 in beside each wall and 36 in between the doors.
The 24 ft 4 in in front of the bumpers takes a typical 6-foot workbench with standing room.
A common garage door is 8 or 9 ft wide, against this footprint’s 30 ft opening wall.
Even with the vehicles and bench in, about 1,001 ft² of the floor stays open.

The big-number math

1200 ft² is slab territory — concrete by the truck, not the bag — and the concrete calculator does yards and loads from this exact footprint. Metal building quotes also price against this number, so it’s worth carrying the precise figure rather than a rounding.

Common questions

How many square feet is a 30x40 room?

A 30×40 room is 1200 square feet — multiply the two wall lengths. That’s 133.33 square yards or 111.48 square meters, and the same answer whether you write it 30x40 or 40x30.

What fits in a 30x40 building?

Two cars park side by side — each is a typical mid-size sedan (about 15 ft 7 in long) — with 90 in beside each wall and 36 in between the doors. A common garage door is 8 or 9 ft wide, against this footprint’s 30 ft opening wall.

How much concrete does a 30x40 slab take?

That depends on the pour depth, which is a project decision — the concrete calculator takes this footprint’s exact 1200 ft² and does yards, bags and truck loads at whatever depth you spec.

The rest of the toolbox

Measured this room? Take the number to whichever material you’re buying — every tool runs in your browser, same as this page.

Square footage calculatorLiveAdd rooms, subtract islands, get one total. Flooring & tile calculatorLiveBoxes needed, waste factor, cost per box. Paint calculatorLiveInterior, exterior with gables, and trim by the foot. Concrete calculatorLiveCubic yards and 60/80 lb bag counts. Roofing calculatorLiveSquares, with the pitch multiplier applied. Mulch & gravel calculatorLiveYards, tons, bags — and truck trips by payload. Sod calculatorLiveRolls and pallets for the area you measured. Room size indexLiveEvery size drawn to scale, with what fits.