Measure in any unit
Get results in all of them
One tap shows square feet, square inches, square yards, square meters, acres and the total cost, ready to copy into a quote or text to a client.
Download on the App Store
Free online tool
Free Square Footage Calculator
Pick a shape, enter your measurements in feet, inches, yards or meters, and press Calculate. You’ll get the area in square feet, square yards, square meters and acres in one go.
Step 2 of 2
Your square footage
0 sq ft
- Square yardsSq yd
- 0
- Square metersm²
- 0
- Square inchesSq in
- 0
- Acres
- 0
- Square feet
- Square inches
- Square yards
- Square meters
- Acres
- Feet + inches input
- No sign-up
Step-by-step
How to Calculate Square Footage
Square footage is the area of a flat surface measured in square feet. Here’s the method the calculator uses, so you can check any number by hand.
- 1
Measure each side
Use a tape measure or laser to record length and width, wall to wall. Round to the nearest inch and note the unit.
- 2
Convert to feet
Turn inches into decimal feet by dividing by 12, so 10 ft 6 in becomes 10.5 ft. Metric? 1 m = 3.281 ft.
- 3
Apply the formula
Multiply length × width for rectangles. Split odd shapes into simple pieces, calculate each, then add them up.
Square footage formulas by shape
| Shape | Formula | Example |
|---|---|---|
| Square / rectangle | Length × Width | 12 × 10 = 120 sq ft |
| Triangle | ½ × Base × Height | ½ × 10 × 8 = 40 sq ft |
| Circle | π × Radius² | 3.1416 × 6² = 113.1 sq ft |
| Trapezoid | (a + b) ÷ 2 × h | (8 + 12) ÷ 2 × 6 = 60 sq ft |
| L-shaped room | (A × B) − (C × D) | (20 × 15) − (8 × 6) = 252 sq ft |
| Any polygon | Shoelace formula on the corner points | Done for you in Areo |
The Areo app
A Square Footage Calculator App That Skips the Math
Formulas work for neat rectangles. Real jobs have angled walls, bump-outs and curved beds. Areo lets you draw the shape you see and does the geometry for you.
Draw to calculate
Trace any outline with your finger. Areo measures every side and shows the square footage live: L-shapes, angled walls, odd lots.
Total cost estimator
Set your price per square foot once and every shape you draw comes with a job total. Quote on the spot, not back at the office.
Concrete & asphalt
Add a depth to any area to get the volume in cubic yards and the cost of pouring a slab, footing or driveway.
Gravel & roofing
Work out gravel for bases and paths, and roofing quantities for every plane, from the same measurements.
Slope & grade
Capture pitch and incline for roofs, ramps and drainage, so the area you price matches the real surface.
Every unit at once
Measure in feet, inches or meters and get square feet, square inches, square yards, square meters and acres together.
How Areo works
From Outline to Quote in Three Taps
- 01
Pick or draw a shape
Start from a square, rectangle, triangle or circle, reuse a saved shape, or draw your own outline point by point.
- 02
Set your unit price
Enter what you charge, or what the material costs, per square foot. Areo remembers it for the next job.
- 03
Get area & cost
Tap Calculate for square footage in every unit plus the total cost. Save the shape for repeat jobs or copy the data.
Who uses Areo
Built for Every Job That Starts With Square Footage
Homeowners planning a renovation, contractors writing bids, landscapers pricing sod, and DIYers buying exactly enough material, not two extra boxes.
Calculate your areaFlooring & tile
Room-by-room area plus waste for hardwood, vinyl, laminate, carpet and tile.
Roofing
Plan area × pitch factor, converted to roofing squares (100 sq ft each).
Concrete slabs
Area × thickness in cubic yards for patios, footings and driveways.
Landscaping & sod
Lawns, garden beds, mulch and gravel paths, including curved edges.
Painting & drywall
Wall and ceiling surface area for paint, primer and drywall sheets.
Real estate
Quick floor-area checks for listings, appraisals and rent per sq ft.
Cheat sheet
Square Footage Conversions & Common Room Sizes
Bookmark these numbers for quotes, material orders and listings.
Area unit conversions
| From | Equals |
|---|---|
| 1 square foot | 144 sq in |
| 1 square foot | 0.0929 m² |
| 1 square yard | 9 sq ft |
| 1 square meter | 10.764 sq ft |
| 1 acre | 43,560 sq ft |
| 1 roofing square | 100 sq ft |
| 1 cubic yard (volume) | 27 cu ft |
Common room sizes in square feet
| Room (ft) | Sq ft | Sq yd | m² |
|---|---|---|---|
| 10 × 10 | 100 | 11.11 | 9.29 |
| 10 × 12 | 120 | 13.33 | 11.15 |
| 12 × 12 | 144 | 16 | 13.38 |
| 12 × 14 | 168 | 18.67 | 15.61 |
| 12 × 16 | 192 | 21.33 | 17.84 |
| 14 × 16 | 224 | 24.89 | 20.81 |
| 15 × 20 | 300 | 33.33 | 27.87 |
| 20 × 20 | 400 | 44.44 | 37.16 |
| 24 × 24 | 576 | 64 | 53.51 |
Pricing
Free to Download. Go Pro When the Job Needs It.
Free
$0
- Draw-to-calculate square footage
- Square, rectangle, triangle & circle templates
- Results in sq ft, sq in, sq yd, m² & acres
- Free web calculator on this site
Most popular with pros
Areo Pro
Free for 3 days, then monthly or quarterly
- Everything in Free
- Concrete & asphalt volume and cost
- Gravel and roofing estimates
- Slope & grade measurement
- Advanced shapes, saved shapes & cost tools
Subscriptions renew automatically and can be cancelled anytime in your Apple ID settings. Local prices are shown in the App Store.
FAQ
Square Footage Questions, Answered
Can’t find what you need? Our guides go deeper on rooms, roofs, concrete and conversions.
How do I calculate square footage?
Measure the length and width of the space in feet and multiply them. A room that is 12 ft long and 10 ft wide is 12 × 10 = 120 square feet. For irregular spaces, split the floor into rectangles, triangles or circles, calculate each one, and add the results together.
How do I calculate square footage if I measured in inches?
Multiply length × width in inches to get square inches, then divide by 144 (because 1 square foot = 12 in × 12 in = 144 sq in). For example, 150 in × 120 in = 18,000 sq in ÷ 144 = 125 sq ft. Or choose "Inches" in the calculator above and it converts for you.
How do I convert square meters to square feet?
Multiply square meters by 10.764. To go the other way, multiply square feet by 0.0929. For example, 20 m² × 10.764 = 215.3 sq ft.
How do I find the square footage of an irregular or L-shaped room?
Divide the room into simple shapes. For an L-shaped room, either split it into two rectangles and add them, or measure the overall rectangle and subtract the missing corner. For truly irregular outlines, the Areo app lets you trace the shape point by point and calculates the exact area for you.
How do I calculate cost per square foot?
Multiply the total square footage by the price per square foot. Add a waste allowance (typically 5–10% for flooring, 10–15% for patterned or diagonal layouts) before multiplying, so you order enough material. 200 sq ft × 1.10 waste × $4 per sq ft = $880.
How many square feet are in a square yard and an acre?
There are 9 square feet in a square yard (3 ft × 3 ft) and 43,560 square feet in an acre. Carpet and sod are often priced by the square yard, so divide your square footage by 9 to compare quotes.
Is the Areo square footage calculator app free?
Yes. Areo is free to download on the App Store and includes draw-to-calculate area. Optional Pro subscriptions, which you can try free for 3 days, unlock advanced tools such as cost estimates for any shape, concrete and asphalt volume, gravel and roofing estimates and slope measurement.
Which devices does Areo work on?
Areo runs on iPhone and iPad with iOS/iPadOS 16.4 or later, on Macs with an Apple M1 chip or later (macOS 12+), and on Apple Vision Pro.
From the blog
Square Footage Guides
How to Calculate Square Footage (Any Shape, With Examples)
Learn how to calculate square footage for rectangles, triangles, circles and odd shapes, with step-by-step formulas, unit conversions and worked examples.
How to Calculate Roof Square Footage Using Roof Pitch
Calculate roof square footage from the ground using footprint area and a roof pitch multiplier, then convert to roofing squares and shingle bundles.
How Much Flooring Do I Need? Square Footage, Waste & Cost
Work out how much flooring to buy: measure square footage, add the right waste factor, convert to boxes or square yards, and estimate the total cost.
Measure Smarter. Quote Faster.
Download Areo, the square footage calculator that turns any shape you draw into area, materials and cost.
Download on the App Store