Square Footage Calculator
Add any number of areas — rectangles, circles, or triangles in feet & inches — to get exact total square footage, unit conversions, and material cost, with a downloadable PDF report.
| Area | Shape | Dimensions | Sq Ft | % of Total | Cost | Size |
|---|---|---|---|---|---|---|
| Calculate to see areas | ||||||
Calculate to see areas
How to use the square footage calculator
Four quick steps turn your measurements into a total in square feet — plus yards, meters, and acres, the material to order with waste, the box count, and a downloadable PDF.
Add each area
Name every room or section and pick its shape — rectangle, circle, or triangle.
Enter feet & inches
Type the dimensions exactly as you measured them — no decimal conversion needed.
Set price & waste
Add your price per sq ft, the coverage per box, and a waste factor.
Read results & save a PDF
Get the total area, conversions, boxes, cost, and a per-area breakdown to download.
How square footage is calculated
Every area comes down to one of three shape formulas, added together. From that total, the waste factor sets the material to order and the coverage per box sets how much to buy. Here is the exact math.
Worked example — a room plus a hallway
Main room: 20' × 15' = 300 sq ft
Hallway: 12' × 4' = 48 sq ft
Total: 300 + 48 = 348 sq ft
Material: 348 × 1.10 (10% waste) = 383 sq ft
Boxes: 383 ÷ 20 = 20 boxes · Cost: 383 × $4.50 = $1,723
≈ 348 sq ft of floor, 383 sq ft of material, 20 boxes, about $1,723 in material.
Square footage charts
Handy lookups for the questions that come up mid-measure — common room sizes, unit conversions, waste factors by install type, and coverage per box.
| Room size | Square feet | Square yards | Square meters |
|---|---|---|---|
| 10 × 10 ft | 100 sq ft | 11.1 yd² | 9.3 m² |
| 12 × 12 ft | 144 sq ft | 16.0 yd² | 13.4 m² |
| 12 × 14 ft | 168 sq ft | 18.7 yd² | 15.6 m² |
| 15 × 15 ft | 225 sq ft | 25.0 yd² | 20.9 m² |
| 20 × 15 ft | 300 sq ft | 33.3 yd² | 27.9 m² |
| 20 × 20 ft | 400 sq ft | 44.4 yd² | 37.2 m² |
Rectangular rooms only. Add closets, alcoves, and bay windows as separate areas so nothing is left out of the total.
| Convert | Multiply / divide | Where it’s used |
|---|---|---|
| Sq ft → sq yards | ÷ 9 | Carpet, sod, and roll goods pricing |
| Sq ft → sq meters | × 0.0929 | Metric quotes and imported material |
| Sq ft → acres | ÷ 43,560 | Lots, land, and large parcels |
| Sq ft → sq inches | × 144 | Tile, trim, and small detail work |
| Sq meters → sq ft | × 10.764 | Reading a metric spec sheet |
Carpet quoted per square yard looks cheaper than the same product per square foot — divide by 9 before comparing prices.
| Install type | Typical waste | Why |
|---|---|---|
| Straight lay, simple room | 5–10% | Few cuts, square walls |
| Standard flooring or carpet | 10% | The common default allowance |
| Many corners, closets, angles | 12–15% | More offcuts per run |
| Diagonal layout | 15% | Every edge piece is cut on an angle |
| Herringbone or large repeat | 15–20% | Pattern matching wastes material |
Waste covers cuts, offcuts, damaged pieces, and the spare you keep for repairs. When in doubt, round up — a short order costs more than a spare box.
| Material | Coverage per unit | Notes |
|---|---|---|
| Laminate / vinyl plank | ~18–24 sq ft per box | Varies by plank length |
| Hardwood | ~20–25 sq ft per bundle | Check the actual bundle label |
| Ceramic / porcelain tile | ~10–15 sq ft per box | Large-format tiles cover less per box |
| Carpet | 12 ft wide roll | Sold by the square yard |
| Sod | ~400–500 sq ft per pallet | Order by the pallet, not the piece |
Coverage differs between products and even between batches — always use the figure printed on the box you’re actually buying.
rooms & halls
nooks & patios
bays & corners
Any floor plan, however awkward, is just simple shapes added together — the trick is splitting it correctly before you measure.
- Split, don’t overlap — an L-shaped room is two rectangles that meet, never two that cross.
- Measure the widest points — take length and width where the room is largest, not at a pinch point.
- Add the small stuff — closets, alcoves, and thresholds are their own areas and still need material.
Everything the calculator works out
One set of measurements gives you the full picture — the area in four units, what to buy, what it costs, and where every square foot came from.
The figures behind every area calculation
Built for any measuring job
Flooring, landscaping, paint, or a listing — the same measurements answer all of them, once they’re in square feet.
Laying floors, tiling a bathroom, or carpeting a bedroom and needs to know exactly how many boxes to bring home.
- Measure at the widest points
- Add 10% for cuts and offcuts
- Keep a spare box for repairs
Pricing a multi-room job and wants a per-area breakdown to hand the client alongside the quote.
- Add each room as its own area
- Set waste by install type
- Save the PDF for the file
Ordering sod or mulch by the pallet, or checking a lot size in acres before making an offer.
- Split the yard into shapes
- Read the total in acres
- Convert to yards for suppliers
7 tips for measuring square footage accurately
Small habits that keep your total honest and stop you making a second trip to the store.
Square footage calculator FAQ
The measuring, conversion, waste, and ordering questions people ask most before buying material.
For a rectangular space, multiply the length by the width in feet. A room 20 feet by 15 feet is 300 square feet. Circles use π × r², and triangles use ½ × base × height.
For an L-shaped or irregular room, split it into simple shapes, work out each one, and add the results together. The calculator does this for any number of areas at once.
Convert the inches to a decimal first by dividing by 12, then multiply the two sides. A wall 12 feet 6 inches long is 12.5 ft, so a room 12’6″ × 10′ is 125 square feet.
Ignoring the inches is where most measuring errors come from, especially across several rooms. The calculator takes feet and inches separately so you never have to do the conversion yourself.
One square yard is 9 square feet, one square meter is about 10.76 square feet, and one acre is 43,560 square feet. Going the other way: ÷ 9 for square yards, × 0.0929 for square meters, ÷ 43,560 for acres.
Carpet is often priced by the square yard, metric quotes come in square meters, and land is sold by the acre, so the same area gets described three different ways.
A waste factor of about 10 percent covers cuts, offcuts, and the odd damaged plank on a straight, simple layout. Diagonal, herringbone, and large-repeat patterns waste far more, so 15 to 20 percent is the usual allowance there.
Rooms with lots of corners, closets, or angled walls sit at the higher end too. Always order the total with waste included rather than the raw floor area.
Break the space into rectangles, circles, and triangles that don’t overlap, measure each one at its widest points, and add the areas together. An L-shaped room is usually two rectangles; a bay window is often a rectangle plus a triangle.
Alcoves, closets, and hallways should be measured as their own areas so nothing gets missed. Adding each piece separately also shows which part of the job is driving the material bill.
Take your total area, add the waste factor, then divide by the coverage printed on the box and round up. If you need 383 square feet and a box covers 20 square feet, that’s 20 boxes.
Coverage varies a lot by product, so check the actual box rather than assuming. Many installers add one spare box from the same batch so future repairs still match.
For a material estimate, include every surface you’re actually covering, so closets and hallways count if they’re getting flooring. For listing a home, finished living space is measured to the exterior walls, and unfinished garages, porches, and most basements are excluded.
The two numbers are measured for different reasons, so they rarely match. Use the material number for buying and the finished-area number for listings and appraisals.
Multiply the area including waste by the price per square foot. At $4.50 a square foot, 383 square feet of material works out to about $1,723 before labor, delivery, or underlayment.
Quotes given by the square yard need dividing by 9 first to compare fairly against a per-square-foot price. The calculator handles the waste, box count, and cost in one step so the numbers stay consistent.
General Estimating Notice: This calculator works out total area, unit conversions, material quantity, and cost from the dimensions, waste factor, coverage, and price you enter. Results depend entirely on the accuracy of your measurements and on product coverage that varies between manufacturers and batches. It does not include labor, underlayment, adhesive, trim, delivery, or taxes, and it is not a measurement standard for listing or appraising a property. Confirm final quantities with your supplier or installer before ordering. For planning purposes only.