Calculate-Compare-Decide
Calculate the area of any room, floor, wall, roof or plot of land — including L-shaped rooms and irregular polygons — and see it drawn to scale as you type. Convert instantly between square feet, meters, yards, acres and hectares, then estimate the flooring, paint, tile or turf you need and what it will cost.
The floor plan and every figure update as you type.
Estimate from your inputs. Always measure twice and check product coverage before buying.
To calculate square footage, multiply length × width in feet. A room 16 ft by 20 ft is 320 square feet. If you measured in inches, divide each measurement by 12 first. For an L-shaped room, split it into two rectangles and add them together. To convert to square meters, multiply square feet by 0.0929.
Five steps. The floor plan draws your actual shape to scale so you can check it before you buy anything.
Rectangle, square, circle, triangle, trapezoid, L-shaped, U-shaped, or a custom polygon for genuinely irregular spaces.
Type your measurements in whatever unit you used — inches through kilometers. Everything converts automatically.
The floor plan redraws to scale with dimension labels. If it does not look like your room, the numbers are in the wrong fields.
Choose flooring, carpet, tile, paint, sod or roofing to get the quantity to buy, and set a waste allowance for offcuts.
See every unit at once plus cost. Then copy, share, print, export CSV, or save the area to compare rooms.
Every area calculation reduces to one of a handful of formulas. Complex rooms are just simple shapes added together.
Either method works. Measuring the overall rectangle and subtracting the missing corner is usually faster and less error-prone than measuring several sub-rooms, because you only need four numbers instead of six.
Example: a room with corners at (0,0), (20,0), (20,10), (10,10), (10,15) and (0,15) works out to exactly 250 ft² — the same as splitting it into a 20 × 10 rectangle plus a 10 × 5 rectangle. Select the polygon shape above to use this for any irregular space.
Example — a 16 × 20 ft living room: area = 320 ft² (29.7 m²). With 10% waste you order 352 ft². In hardwood at 20 ft² per box that is 18 boxes; at $6 per ft² the material runs $1,920.
Typical sizes with the area in every common unit, calculated with the same formulas as the tool above.
| # | Space | Dimensions | Square feet | Square meters | Square yards |
|---|---|---|---|---|---|
| 1 | Small bedroom | 10 × 10 ft | 100.0 ft² | 9.3 m² | 11.1 yd² |
| 2 | Master bedroom | 14 × 16 ft | 224.0 ft² | 20.8 m² | 24.9 yd² |
| 3 | Guest bedroom | 11 × 12 ft | 132.0 ft² | 12.3 m² | 14.7 yd² |
| 4 | Living room | 16 × 20 ft | 320.0 ft² | 29.7 m² | 35.6 yd² |
| 5 | Family room | 18 × 24 ft | 432.0 ft² | 40.1 m² | 48.0 yd² |
| 6 | Kitchen | 12 × 14 ft | 168.0 ft² | 15.6 m² | 18.7 yd² |
| 7 | Galley kitchen | 8 × 16 ft | 128.0 ft² | 11.9 m² | 14.2 yd² |
| 8 | Full bathroom | 8 × 10 ft | 80.0 ft² | 7.4 m² | 8.9 yd² |
| 9 | Half bath | 5 × 6 ft | 30.0 ft² | 2.8 m² | 3.3 yd² |
| 10 | Home office | 10 × 12 ft | 120.0 ft² | 11.1 m² | 13.3 yd² |
| 11 | Dining room | 12 × 16 ft | 192.0 ft² | 17.8 m² | 21.3 yd² |
| 12 | Hallway | 4 × 25 ft | 100.0 ft² | 9.3 m² | 11.1 yd² |
| 13 | Single garage | 12 × 22 ft | 264.0 ft² | 24.5 m² | 29.3 yd² |
| 14 | Double garage | 20 × 22 ft | 440.0 ft² | 40.9 m² | 48.9 yd² |
| 15 | Basement | 30 × 40 ft | 1,200.0 ft² | 111.5 m² | 133.3 yd² |
| 16 | Warehouse bay | 50 × 100 ft | 5,000.0 ft² | 464.5 m² | 555.6 yd² |
| 17 | Retail unit | 25 × 60 ft | 1,500.0 ft² | 139.4 m² | 166.7 yd² |
| 18 | Patio | 14 × 18 ft | 252.0 ft² | 23.4 m² | 28.0 yd² |
| 19 | Deck | 12 × 16 ft | 192.0 ft² | 17.8 m² | 21.3 yd² |
| 20 | Driveway | 12 × 50 ft | 600.0 ft² | 55.7 m² | 66.7 yd² |
| 21 | Front lawn | 40 × 60 ft | 2,400.0 ft² | 223.0 m² | 266.7 yd² |
| 22 | Back garden | 30 × 50 ft | 1,500.0 ft² | 139.4 m² | 166.7 yd² |
| 23 | Roof plane | 28 × 40 ft | 1,120.0 ft² | 104.1 m² | 124.4 yd² |
| 24 | Studio apartment | 22 × 25 ft | 550.0 ft² | 51.1 m² | 61.1 yd² |
| 25 | Bedroom (metric) | 3.5 × 4 m | 150.7 ft² | 14.0 m² | 16.7 yd² |
| 26 | Living room (metric) | 5 × 6.5 m | 349.8 ft² | 32.5 m² | 38.9 yd² |
| 27 | Kitchen (metric) | 3.6 × 4.2 m | 162.8 ft² | 15.1 m² | 18.1 yd² |
| 28 | Villa floor (metric) | 12 × 15 m | 1,937.5 ft² | 180.0 m² | 215.3 yd² |
| 29 | Terrace (metric) | 4 × 9 m | 387.5 ft² | 36.0 m² | 43.1 yd² |
| 30 | Office floor (metric) | 15 × 20 m | 3,229.2 ft² | 300.0 m² | 358.8 yd² |
Figures are the measured floor area before any waste allowance. Add your waste percentage before ordering material.
What the numbers mean before you order material or sign a quote.
What your space actually covers. Use this figure for comparing quotes, valuing property, and any calculation where the real area matters.
Measured area plus waste. Offcuts, pattern matching and breakage mean you always buy more than you measure — this is the number to give a supplier.
Materials are sold in packages, not square feet. The unit count is rounded up because you cannot buy two-thirds of a box of flooring.
The great equaliser. Converting every quote to a price per square foot makes wildly different bids directly comparable.
A square footage figure is abstract until you compare it to something familiar. Both charts update live.
Your area against everyday reference spaces, so you can sanity-check the number.
How many units of each material your order area needs.
Flooring a whole house means adding up every room. Enter each one here for a single combined total and order figure.
Your measured area and order area in every common unit, updated live.
| Unit | Measured area | Order area (with waste) |
|---|
How much ground each package covers, and how much extra to allow. These figures are built into the calculator.
| Material | Sold as | Typical coverage | Waste to allow | Notes |
|---|---|---|---|---|
| Hardwood flooring | Box | 20 ft² per box | 10–15% | More for diagonal or herringbone layouts |
| Laminate | Box | 24 ft² per box | 10% | Check the pack — coverage varies by plank size |
| Vinyl plank (LVP) | Box | 24 ft² per box | 10% | Forgiving to cut; 5% for simple rooms |
| Carpet | Square yard | 9 ft² per yd² | 10–20% | Roll width and pattern repeat drive waste |
| Tile | Piece / box | by tile size | 10–15% | 15% for diagonal, mosaic or many cuts |
| Paint | US gallon | 350 ft² per coat | — | Two coats standard; porous surfaces cover less |
| Wallpaper | Double roll | 28 ft² usable | 15–20% | Pattern repeat significantly increases waste |
| Sod / turf | Pallet | 450 ft² per pallet | 5–10% | Lay within 24 hours of delivery |
| Artificial grass | Roll (ft²) | by roll width | 10–15% | Pile direction must run consistently |
| Roofing | Square | 100 ft² per square | 10–15% | Add for hips, valleys and starter courses |
| Mulch | Cubic yard | 108 ft² at 3 in | 5–10% | Depth drives quantity — 2–4 in typical |
| Concrete | Cubic yard | 81 ft² at 4 in | 10% | Uneven subgrade absorbs more than expected |
Coverage figures are industry typicals for estimating. Always check the actual coverage printed on the product you buy, since it varies by manufacturer and product line.
A square foot is the area of a square measuring one foot on each side. It is the standard unit of area in the United States, Canada and parts of Asia and the Middle East, used for everything from quoting flooring to listing real estate. One square foot equals 144 square inches, about 0.0929 square meters, or one ninth of a square yard. Because it describes area rather than length, it scales with the square of the dimensions: doubling both the length and width of a room quadruples its square footage.
That squaring effect is worth internalising, because it is where intuition fails. A 12 × 12 ft room is 144 ft²; a 16 × 16 ft room feels only slightly larger but is 256 ft² — nearly 80% more floor to cover and pay for.
For a rectangular space, measure the length and the width in feet and multiply them. A room 16 ft long and 20 ft wide is 320 square feet. If you measured in inches, divide each measurement by 12 before multiplying, or convert the final result by dividing by 144. Never multiply a measurement in feet by one in inches — mixing units in a single calculation is the most common source of wrong answers.
For anything that is not a simple rectangle, you have two options: use the formula for that shape, or break the space into rectangles and triangles you can calculate separately and add together. Both give the same answer, and the calculator above supports either approach.
A square is its side squared. A circle is π times the radius squared, where the radius is half the diameter — measuring the diameter and halving it is far more reliable than trying to find the exact centre. A triangle is half the base times the perpendicular height, not the length of a sloping side. A trapezoid averages the two parallel sides and multiplies by the distance between them. Every one of these reduces to the same idea: find an equivalent rectangle.
Most real rooms are not clean rectangles. For an L-shaped room, the fastest method is to measure the overall rectangle as if the missing corner were filled in, then measure the missing corner and subtract it. Four measurements instead of six, and fewer chances to mismeasure. A U-shaped room works the same way with a central notch removed.
For genuinely irregular spaces — angled bay windows, splayed walls, odd lot boundaries — the professional approach is the surveyor's formula, also called the shoelace formula. You record the coordinates of each corner going around the outline, and the formula returns the exact area regardless of how strange the shape is. The polygon option in the calculator does this, and it will handle any outline you can plot.
The conversions that matter: one square meter is 10.764 square feet, and one square foot is 0.0929 square meters. A square yard is exactly nine square feet, which is why carpet sold by the yard needs a division by nine. For land, one acre is 43,560 square feet and one hectare is 10,000 square meters, or about 2.471 acres. If a supplier quotes in one system and your measurements are in another, convert once at the end rather than converting each measurement — it reduces rounding drift.
Measure at floor level, not at waist height, since walls are rarely perfectly plumb. Take each dimension at both ends of the room; if they differ, use the larger figure for ordering material and note the discrepancy, because it means the room is out of square and you will need extra for scribing. Include alcoves, bay windows, closets and doorway thresholds if they will be covered, and measure them as separate small rectangles to add on.
Sketch the room before you measure and write dimensions directly on the sketch. Almost every ordering disaster starts with a number written next to the wrong wall rather than with the arithmetic. For large or awkward spaces, a laser distance meter is inexpensive and removes the sag and slack that a tape introduces over long runs.
Flooring is sold by the box with a stated coverage — commonly around 20 ft² for hardwood and 24 ft² for laminate and vinyl plank. Divide your order area by the box coverage and round up, then buy at least one extra box: dye lots vary between production runs, and a plank damaged in year three is impossible to match without a spare. Ten percent waste suits a straightforward rectangular room; allow 15% for diagonal or herringbone layouts, which generate far more offcuts.
Carpet is different because it comes off a roll of fixed width, usually 12 ft. A room wider than the roll needs a seam, and the way the roll is cut can waste a surprising amount. Carpet is priced by the square yard in many markets — divide square feet by nine — and patterned carpet needs additional material so the pattern lines up across seams.
Paint coverage is quoted per gallon per coat, typically around 350 ft². Note that painting is a wall area calculation, not a floor one: measure the perimeter of the room, multiply by the ceiling height, and subtract windows and doors. Most jobs need two coats, and porous or previously unpainted surfaces will drink noticeably more than the label suggests.
Wallpaper is sold in rolls with roughly 28 usable square feet per double roll after trimming. Patterned papers need extra for the repeat — the taller the repeat, the more you waste at every drop — so 15 to 20 percent extra is normal rather than cautious.
Tile quantity is your order area divided by the area of one tile. A 12 × 12 in tile is exactly one square foot, which makes the arithmetic easy; a 12 × 24 in tile covers two. Add 10% for a straight layout and 15% for diagonal, mosaic or heavily cut rooms. Buy a full extra box beyond that for future repairs, since tile lines are discontinued constantly and matching later is often impossible.
Land is where acres and hectares take over. An acre is 43,560 ft² — roughly a square 209 ft on a side, or about 90% of an American football field excluding the end zones. A hectare is 10,000 m², about 2.47 acres. Lot dimensions are usually quoted as frontage by depth, so a 100 × 150 ft lot is 15,000 ft², or about 0.34 acres. For irregular parcels, the polygon tool and the surveyor's formula are exactly what land surveyors use.
Real estate square footage follows conventions that differ from a simple floor measurement. Listings in the US typically report gross living area — finished, heated space measured to the exterior walls — which excludes garages, unfinished basements and often excludes rooms with low ceilings. Different standards exist, and measurement practice varies between markets and appraisers, so a listed figure and your own tape measure will rarely agree exactly. For buying, selling or appraising, follow the standard your local market uses rather than a generic calculation.
The questions people ask most about square footage. Tap any question to expand.