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How many square feet is my room, and what actually fits in it? Enter the width and the length — this room size calculator returns the area, then looks your two dimensions up against our own published tables for living rooms, bedrooms and dining rooms, and names what the room is too small for. Rooms in feet, furniture in inches.
Measure wall to wall at floor level. A builder's plan is usually dimensioned to framing, so the finished room is smaller than the number printed on the sheet — assume you have less than it claims until a tape says otherwise.
Square footage is width times length and nothing else. It is genuinely useful — for flooring, for paint, for a listing, for comparing one house against another. It is close to useless for deciding whether a sofa fits, and the reason is one line of arithmetic: 168 square feet is a 12 × 14 room and it is also a 7 × 24 room. One of those takes a sectional and a dining table. The other takes a hallway runner.
Furniture fits against dimensions. An 84-inch sofa needs 84 inches of something, and no amount of area on the other axis will supply it. That is why every verdict this calculator returns is tested against the short wall and the long wall separately, and why the square footage above is reported as a fact rather than used as a gate. It is also why the tables below are all published as pairs of feet rather than as areas.
The second reason is subtler. Two rooms of identical dimensions can behave completely differently depending on where the door, the closet and the windows land — a 12 × 14 bedroom with the bed on the 12-foot wall gives you two usable side walls, and the same 12 × 14 with the bed on the 14 gives you one. Nothing on this page can see that. A floor plan can.
There is no such thing as a living-room size. There are layouts, and each one wants a room. These are the four our living-room guide publishes, and the sizes given are the ones at which each layout is comfortable — not the minimum at which it is physically possible.
| Layout | Room | Notes |
|---|---|---|
| Sofa facing a TV wall | 11 × 13′ | the default; check the viewing distance |
| Sofa + two chairs | 13 × 15′ | the conversational one; chairs angled in |
| Sectional + chair | 13 × 16′ | the chaise leg eats a whole walkway |
| Two sofas facing | 14 × 16′ | formal; hold the 8-foot conversation rule |
An open-plan great room is easier than its square footage suggests, because the walkway can run outside the seating group instead of through it. That is the whole trick of arranging a big room, and it is the one case where the table above understates what you have.
There is no published standard bedroom size. What there is, is what American builders actually draw, and what the wall arithmetic does to a bed once you put one in. These verdicts count the frame — a frame adds 2–5″ per axis, so a queen plans at about 65 × 85 and a king at about 81 × 85 — and they count a dresser, which commits its depth plus 36″ of standing room.
| Room | Bed | What the math says |
|---|---|---|
| 10 × 10 | Full | full leaves ~31″ per side; a queen drops that to ~27″ with no wall left for a dresser beside it |
| 10 × 12 | Queen | the standard secondary bedroom: queen on the 10′ wall, dresser opposite the foot |
| 11 × 13 | Queen, king tight | queen plus dresser and a chair; a king works only with clear side walls |
| 12 × 12 | King — conditionally | ~31″ per side if nothing else lives on those walls; the door swing is the judge |
| 12 × 14 | King | king plus dresser without squeezing the walkways |
| 13 × 15 + | King + extras | primary-suite territory: bench at the foot, chair, double dressers |
The calculator reports the largest row in this table that your room contains — both dimensions at once. A 12 × 13 room contains the 12 × 12 row and does not contain the 12 × 14 row, so it gets the conditional king, and the condition is the same one: nothing else on those side walls.
A dining table's real footprint is not the table. It is the table plus 36″ of chair pull-back on every side — the distance a chair travels to let an adult sit down and stand up again. That is the single most commonly skipped number in furnishing a house, and it is why a table that measured fine against the room turns out to be unusable at two seats.
A 72 × 36 table therefore wants a clear 144 × 108 inches — twelve feet by nine — before anything else lives in the room. A 60-inch round wants a circle 132 inches across, so an 11-foot room in both directions. Where a path runs behind the seated diners rather than stopping at the chair, that side wants 42–48″ instead of 36.
| Table | Seats | Clear floor at 36″ all round |
|---|---|---|
| 48 × 36 | 4 | 120 × 108″ — 10′-0″ × 9′-0″ |
| 60 × 36 | 4–6 | 132 × 108″ — 11′-0″ × 9′-0″ |
| 72 × 36 | 6 | 144 × 108″ — 12′-0″ × 9′-0″ |
| 84 × 40 | 6–8 | 156 × 112″ — 13′-0″ × 9′-4″ |
| 96 × 42 | 8–10 | 168 × 114″ — 14′-0″ × 9′-6″ |
| 60″ round | 6–8 | 132 × 132″ — 11′-0″ square |
Everything above is a lookup and a multiplication. The lookups are our own published tables — the living room layout guide, the bedroom sizes guide and the dining table guide — and the arithmetic is exact. Nothing here is invented, and where a figure is a design convention rather than a published standard, the guide it came from says so on its own page.
What it cannot do is see your room. Closets, windows, radiators, a return-air grille, and the door's quarter-circle of dead floor are the things that actually decide a layout, and none of them are in a width and a length. So read the verdict as a floor rather than a promise: if the arithmetic fails, the room fails. If the arithmetic passes, the plan still gets a vote.
Multiply the width in feet by the length in feet. A room 12 feet by 14 is 168 square feet. Measure wall to wall at floor level rather than at waist height, because baseboard steals about an inch on each wall and it steals it exactly where furniture feet want to sit. For an L-shaped room, split it into two rectangles, work each one out, and add them together.
144 square feet, or 144 × 144 inches. That is the room our bedroom guide calls a conditional king: a king with its frame is about 81″ wide on a 144″ wall, leaving roughly 31″ per side if you centre it and nothing else lives on those two walls. As a living room it is under the 11 × 13 our living-room guide gives the simplest layout, and as a dining room it takes a 72 × 36 table with the full 36″ of chair pull-back on every side.
It depends entirely on the layout you want, which is why we publish rooms per layout rather than one number. A sofa facing a TV wall is comfortable at 11 × 13 feet. A sofa with two chairs turned in wants 13 × 15. A sectional with a chair wants 13 × 16, and two sofas facing each other want 14 × 16. Those are the sizes at which each layout is comfortable, not the minimum at which it is possible.
Add 36″ of chair pull-back to every side of the table. A 72 × 36 table therefore wants a clear 144 × 108″ — twelve feet by nine — before anything else lives in the room. A 60-inch round wants a circle 132″ across, so an 11-foot room. If a path has to run behind the seated diners, widen that side to 42 or 48.
No, and anyone quoting one is quoting a market habit rather than a published standard. What American builders actually draw is 10 × 10 and 10 × 12 for secondary bedrooms, 11 × 13 where the plan is generous, and 12 × 14 up to 14 × 16 for a primary suite. The useful question is which bed the walls take once the door swing, the closet and the windows have had their say.
Not on its own, and this is the single most useful thing to know about room size. 168 square feet is a 12 × 14 or a 7 × 24, and the second one takes almost no furniture at all. Furniture fits against dimensions, not against area — which is why every verdict this calculator returns is tested against both the short wall and the long one, and why the square footage is reported as a fact rather than used as a test.
The demo plan is ours and it is public — no account, nothing to upload. Open it, drag a sofa and a bed around a drawing at true scale, and watch the clearances do this whole page for you with the door swings in place.
Open the demo plan →