Instantly calculate square feet for any room, house, or flooring project — no math required. Supports rectangles, L-shaped rooms, triangles, and circles.
⚡ Results in seconds📐 4 shapes supported💰 Cost estimates included📱 Works on any device
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Square Footage Calculator
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💡 Tip: Split your L-shaped room into two rectangles. Measure each section and enter below — we'll add them together for you.Section A
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What Is Square Footage — and Why Does It Matter?
Square footage is the total area of a flat surface measured in square feet. Think of it as counting how many 1-foot × 1-foot squares fit inside a space — roughly the size of a standard floor tile. When you line up enough of them, you get the square footage of a room, a house, or an entire yard.
It matters more than most homeowners expect. Contractors quote flooring, painting, and tiling jobs per square foot. Real estate listings use it to compare homes. Home improvement stores sell materials by the square foot. If you don't know your numbers going in, you'll either buy too much — wasting money — or too little, meaning an extra trip to the store mid-project.
📌 Quick fact: The average American home sits around 2,300 square feet — but most renovation projects involve just one or two rooms at a time, typically between 100 and 300 sq ft each.
How to Calculate Square Footage of a Room
The formula is refreshingly simple. For any rectangular room:
Square Footage = Length × WidthBoth measurements must be in feet for the result to be in sq ft
A bedroom that's 12 feet long and 10 feet wide? That's 120 square feet. A kitchen that's 14 × 11 ft? That's 154 sq ft. Enter your numbers in the calculator above — no math needed on your end.
Step-by-Step for Any Room
1Grab a tape measure. A standard tape measure works for most rooms. For larger spaces, a laser measurer saves time.
2Measure the length. Pull the tape from wall to wall. Write it in feet — if it's 11 ft 6 in, write 11.5.
3Measure the width. Same thing, perpendicular to your first measurement.
4Multiply length × width — or enter both numbers in the calculator above for instant results.
5For L-shaped rooms: Divide into two rectangles, calculate each section separately, then add them together. The L-Shape tab does this automatically.
💡 Pro Tip: Always measure to the farthest walls, not to furniture or kitchen islands. For flooring, measure the full floor — you'll account for fixed obstacles when placing your order.
If Your Measurements Are in Inches
Switch the unit selector on the calculator to "Inches" and it converts automatically. Or do it manually: divide each measurement by 12 to get feet, then multiply. Example: 144 in × 120 in = 12 ft × 10 ft = 120 sq ft.
Common Room Sizes — Square Footage Chart
Not sure how big your room is in square feet? Here are the most common dimensions as a quick reference before your next flooring or renovation project.
Room Dimensions
Square Footage
Typical Use
Flooring (+ 10%)
8 × 8 ft
64 sq ft
Small bathroom / closet
~70 sq ft
10 × 10 ft
100 sq ft
Small bedroom / nursery
~110 sq ft
10 × 12 ft
120 sq ft
Average bedroom
~132 sq ft
12 × 12 ft
144 sq ft
Standard bedroom
~158 sq ft
12 × 15 ft
180 sq ft
Large bedroom / small living room
~198 sq ft
15 × 15 ft
225 sq ft
Medium living room
~248 sq ft
15 × 20 ft
300 sq ft
Large living room
~330 sq ft
20 × 20 ft
400 sq ft
Open plan / garage
~440 sq ft
*Flooring estimates include 10% overage for cuts and waste. For diagonal patterns, use 15%.
When Do You Need to Know Square Footage?
Square footage shows up in more home projects than you'd expect. Here's a quick rundown of the most common situations — and what to keep in mind for each one.
🪵FlooringHardwood, LVP, laminate, tile, and carpet are all sold by the square foot. Know your area before you shop.Add 10% for waste
🎨PaintingOne gallon covers ~350–400 sq ft. Calculate your wall area before buying paint to avoid shortages.Divide by 375 = gallons
🟫TileBathroom, kitchen, and garage floors all need accurate square footage for tile orders.Add 15% for diagonal
🏠Real EstateVerify a home's listed sq footage before buying, or measure your own before listing for sale.Measure finished spaces
🌿LandscapingCalculate lawn area for sod, mulch, grass seed, or pavers. L-shape mode handles most yards.L-shape for odd yards
🌡️HVAC SizingAir conditioner and heater sizing is based on room square footage. Get it right to avoid energy waste.~20 BTU per sq ft
Square Footage Conversion Chart
Working with metric measurements or international suppliers? Here are the conversions you'll actually use:
1 Square Foot↕0.0929 m²× 0.0929
1 Square Meter↕10.764 sq ft× 10.764
1 Square Yard↕9 sq ft× 9
1 Acre↕43,560 sq ftstandard
1 Square Inch↕0.00694 sq ft÷ 144
1 Hectare↕107,639 sq ftmetric land
Frequently Asked Questions
Real questions people search for — answered plainly, without the fluff.
Measure the length and width of your room in feet, then multiply them. A 12 ft × 10 ft room = 120 sq ft. For L-shaped or irregular spaces, divide into rectangles, calculate each one, and add the totals together.
A 12×12 room is exactly 144 square feet (12 × 12 = 144). This is one of the most common bedroom sizes in the US. For flooring, purchase around 158 sq ft to include a 10% waste factor during installation.
Always add 10% to your measured square footage. This covers edge cuts, waste during installation, and spare pieces for future repairs. For diagonal layouts, go with 15%. Running short mid-install is far worse than having a few extra planks.
For interior projects like flooring and painting, always measure inside wall to wall. For real estate listings, square footage typically includes wall thickness. Unfinished spaces like unheated garages are usually excluded from livable square footage.
Multiply your square footage by 0.0929. Example: 500 sq ft × 0.0929 = 46.45 square meters. Going the other way, multiply square meters by 10.764. Or just switch the calculator above to "Meters" for automatic conversion.
Mentally split the L shape into two rectangles. Measure each rectangle separately, calculate each area (length × width), then add the two totals. The L-Shape tab in the calculator above handles all of this automatically.
One acre equals exactly 43,560 square feet. To picture it — an American football field including end zones is about 48,000 sq ft, so an acre is slightly smaller. Multiply any acreage by 43,560 to convert to square feet.
Wall sq footage is different from floor sq footage. Multiply ceiling height by the total room perimeter. For a 12×10 room with 9-ft ceilings: perimeter = 44 ft, wall area = 396 sq ft. Subtract ~20 sq ft per door and ~15 sq ft per window. One gallon covers 350–400 sq ft per coat.
