Room Square Footage Calculator
One room rarely means one rectangle. Measure the main area, add the alcove or the L-shaped leg as a second row, and the calculator keeps a running total — ready for flooring, carpet, paint or a listing.
| Areas added | — |
| Cut-outs subtracted | — |
| Net area | — |
| In square yards | — |
| In square meters | — |
| In acres | — |
| Area incl. waste | — |
| Estimated material cost | — |
Everything is calculated locally in your browser — no measurements are sent anywhere. Mixed units are converted exactly (1 ft = 0.3048 m, 1 sq yd = 9 sq ft, 1 acre = 43,560 sq ft).
How to measure a room in four steps
1. Sketch the outline. A rough floor plan on paper, with a box for every rectangular piece. Most "irregular" rooms are two rectangles and maybe a triangle under a bay window.
2. Measure wall to wall, at floor level. Baseboards (skirting) and slightly bowed walls eat inches you only discover when the last plank won't fit — measure the longest points. Our full measuring guide covers the details.
3. Round up, not down. Round each measurement up to the nearest inch before entering it. An inch of slack costs almost nothing; an inch short costs a trip back to the store.
4. Add waste before you price. 10% for straight layouts is the safe default already filled in above.
Worked example
The preset room above is a 12 × 10 ft main area (120 sq ft) with a 5 × 3 ft reading nook (15 sq ft): 135 sq ft net, 15 sq yd, or 12.54 m². With 10% waste you would order flooring for 148.5 sq ft.
What the number is used for
| Job | What else to add |
|---|---|
| Flooring & carpet | 5–15% waste by pattern; see the flooring calculator |
| Paint | You need the wall area, not the floor area |
| Heating / AC sizing | Ceiling height and insulation matter as much as area |
| Rentals & listings | State what you measured — listing conventions differ by market |
Room questions
Do closets count in a room's square footage?
For buying flooring, yes — the closet floor gets covered too, so add it as its own row. For listing or appraisal purposes, closets inside a bedroom are normally included in that room, while separate storage may be treated differently. This calculator gives you the physical area; how a listing counts it is a convention, not math.
What about a room with a sloped ceiling or bay window?
The floor area is still length × width of the floor outline — a bay is usually a trapezoid or a rectangle plus a shallow triangle. Add it as an extra row with the matching shape.
My room is in meters. Do I have to convert first?
No. Set the row's unit to m (or cm) and type the numbers as measured. Conversion is exact and automatic.
Measuring a whole house? The house square footage page starts with a full set of room rows. Painting instead? Use the wall calculator.