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Square Footage Calculator

Calculate area for any space

Total Square Footage

444.0

Rooms

2

sq m

41.25

Units
Area300.00 sq ft
Area144.00 sq ft

Room Comparison

Living Room300.0 sq ft
Bedroom144.0 sq ft

Room Breakdown

Living Room300.00 sq ft
Bedroom144.00 sq ft

Total in sq m

41.25

444.00 sq ft = 41.25 sq m

Rooms

2

Avg Room Size

222

sq ft

What You'll Need

BOSCH GLM20 Blaze 65ft Laser Distance Measure

BOSCH GLM20 Blaze 65ft Laser Distance Measure

$30-$504.6
View on Amazon
Stanley FatMax 25ft Magnetic Tape Measure

Stanley FatMax 25ft Magnetic Tape Measure

$20-$304.6
View on Amazon
BOSCH GLM20 Blaze 65ft Laser Distance Measure

BOSCH GLM20 Blaze 65ft Laser Distance Measure

$30-$504.6
View on Amazon
Stanley FatMax 25ft Magnetic Tape Measure

Stanley FatMax 25ft Magnetic Tape Measure

$20-$304.6
View on Amazon

As an Amazon Associate, we earn from qualifying purchases.

Frequently Asked Questions

Q

How do I calculate square footage of a room?

Length (ft) × Width (ft) = Square feet. For a 12×15 room: 12 × 15 = 180 sq ft. For irregular rooms, divide into rectangles, calculate each, then add together. Always measure to the nearest inch for accuracy.

  • Rectangle: Length × Width
  • Circle: π × radius² (3.14 × r²)
  • Triangle: ½ × base × height
  • Irregular: Divide into simple shapes, add together
  • Measure in feet, convert inches to decimals
Room SizeSquare FeetCommon Room Type
10×10100 sq ftSmall bedroom
12×12144 sq ftStandard bedroom
12×15180 sq ftMaster bedroom
15×20300 sq ftLiving room
10×12120 sq ftHome office
Q

How do I convert square feet to other units?

Sq ft to sq meters: × 0.0929. Sq ft to sq yards: ÷ 9. Sq ft to acres: ÷ 43,560. Common uses: Real estate uses sq ft, carpet uses sq yards, land uses acres.

  • 1 sq yard = 9 sq ft (carpet industry)
  • 1 acre = 43,560 sq ft (land/real estate)
  • 1 sq meter = 10.764 sq ft (international)
  • Hectare = 2.471 acres = 107,639 sq ft
FromToFormulaExample
Sq ftSq meters× 0.0929100 sq ft = 9.29 sq m
Sq ftSq yards÷ 9180 sq ft = 20 sq yd
Sq ftAcres÷ 43,56021,780 sq ft = 0.5 acre
Sq metersSq ft× 10.76450 sq m = 538 sq ft
Q

What is the average square footage by home type?

Average US home: 2,300 sq ft. Studio apartment: 400-600 sq ft. 1-bedroom: 700-900 sq ft. 2-bedroom: 900-1,200 sq ft. 3-bedroom house: 1,500-2,200 sq ft. McMansion: 3,500+ sq ft.

  • Average US home has grown 50% since 1970
  • NYC average: 866 sq ft
  • Suburban average: 2,500+ sq ft
  • Tiny homes: 100-400 sq ft
Home TypeTypical SizeNotes
Studio apartment400-600 sq ftNo separate bedroom
1-bed apartment700-900 sq ftCity average
2-bed apartment900-1,200 sq ftCommon rental
3-bed house1,500-2,200 sq ftAverage family home
4-bed house2,200-3,000 sq ftLarger family
McMansion3,500+ sq ftNew construction
Q

How do I calculate square footage for flooring?

Measure room length × width for each room. Add all rooms together. Add 10-15% for waste/cuts. Flooring is sold by sq ft or box (usually 20-25 sq ft per box). Round up to full boxes.

  • Measure each room separately
  • Include closets if flooring them
  • Add 10% waste for simple rooms
  • Add 15% for diagonal or complex patterns
  • Add 5% more to keep for repairs
  • Flooring boxes: Usually 20-25 sq ft each
Room Sq Ft+10% Waste+15% WasteBoxes (20 sq ft)
1001101156 boxes
20022023012 boxes
50055057529 boxes
Q

How do I measure wall square footage for paint?

Wall area = Perimeter × Height. Perimeter = 2×(Length + Width). For a 12×15 room with 8ft ceilings: Perimeter = 54 ft. Wall area = 54 × 8 = 432 sq ft. Subtract 20 sq ft per door, 15 per window.

  • Perimeter = 2 × (Length + Width)
  • Wall area = Perimeter × Ceiling height
  • Subtract: 20 sq ft per door
  • Subtract: 15 sq ft per window
  • One gallon covers 350-400 sq ft
  • Most rooms need 2 coats
Q

How is square footage calculated for real estate?

Real estate uses Gross Living Area (GLA): All heated/cooled living space. Includes: Bedrooms, bathrooms, living areas, hallways, closets. Excludes: Garage, unfinished basement, porches, patios. Measured exterior wall to exterior wall.

  • GLA = Gross Living Area (heated/finished)
  • Measure exterior walls (includes wall thickness)
  • Include: Finished basement (sometimes discounted)
  • Exclude: Garage, unfinished areas, porches
  • Appraisers use ANSI standards
  • Second story with lower ceiling: May be discounted

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Example Calculations

1Two-Room Home (Living Room + Bedroom)

Inputs

Living Room20 × 15 ft (rectangle)
Bedroom12 × 12 ft (rectangle)

Result

Total Square Footage444.00 sq ft
Living Room Area300.00 sq ft
Bedroom Area144.00 sq ft

Living room = 20 × 15 = 300 sq ft. Bedroom = 12 × 12 = 144 sq ft. Total = 300 + 144 = 444.00 sq ft.

2Mixed Shapes (Rectangle + Circular Area)

Inputs

Main Room18 × 14 ft (rectangle)
Turret/NookRadius 5 ft (circle)

Result

Total Square Footage330.54 sq ft
Main Room Area252.00 sq ft
Turret/Nook Area78.54 sq ft

Main room = 18 × 14 = 252 sq ft. Circular nook = pi × 5² = 3.14159 × 25 = 78.54 sq ft. Total = 252 + 78.54 = 330.54 sq ft.

Formulas Used

Rectangle Area

Area = Length × Width

Standard area formula for rectangular rooms.

Where:

Length= Room length (ft or m)
Width= Room width (ft or m)

Circle Area

Area = pi × Radius²

Area of a circular space.

Where:

pi= 3.14159...
Radius= Distance from center to edge (ft or m)

Triangle Area

Area = (Base × Height) / 2

Area of a triangular space.

Where:

Base= Length of the base (ft or m)
Height= Perpendicular height (ft or m)

Complete Guide to Measuring Square Footage

1

Why Accurate Square Footage Matters for Every Project

A 5% measurement error on a 2,000 sq ft home translates to 100 sq ft of miscalculated space — enough to throw off a $15,000 flooring order by $750 or skew a property appraisal by $10,000–$20,000. Real estate agents, contractors, and appraisers all rely on precise square footage to price homes, order materials, and comply with building permits.

The average American home measures 2,299 sq ft as of 2023 (U.S. Census Bureau), up from roughly 1,500 sq ft in 1970. That 53% increase means more rooms, more complex floor plans, and more opportunities for measurement errors. Whether you are listing a home or planning a renovation, getting the area right saves money and prevents disputes.

For construction projects, square footage drives material quantities: paint (350–400 sq ft per gallon), flooring (sold in 20–25 sq ft boxes), and tile (priced per sq ft). Underestimating by even 10% can stall a project mid-job while you wait for a second delivery.

Tip: Always measure to the nearest inch and convert fractions to decimals (e.g., 12’ 6” = 12.5 ft) before multiplying.

2

How to Calculate Area for Different Shapes

Rectangular rooms use the simplest formula: Length × Width. A 12 × 15 ft bedroom yields 180 sq ft. For L-shaped rooms, split the space into two rectangles, calculate each, and add the results — a common 10 × 12 ft section plus a 6 × 8 ft alcove totals 168 sq ft.

Circular areas use π × r². A round breakfast nook with a 5 ft radius covers 78.54 sq ft. Triangular spaces — such as an under-stair closet — use ½ × Base × Height: a 6 × 4 ft triangle is just 12 sq ft. Irregular rooms should be broken into simple shapes, measured individually, and summed.

Wall area for paint uses the perimeter method: Perimeter × Ceiling Height, minus 20 sq ft per door and 15 sq ft per standard window. A 12 × 15 ft room with 8 ft ceilings, two windows, and one door has roughly 382 sq ft of paintable wall.

Common Area FormulasL = 15 ftW = 12180 sq ftL × Wr=5 ft78.5 sq ftπ × r²b = 8 fth=624 sq ft½ × b × hRectangleCircleTriangle
3

Square Footage by Room and Home Type

National averages provide useful benchmarks when planning layouts. The median single-family home in the US has 2,299 sq ft, while studios average 504 sq ft and one-bedroom apartments about 757 sq ft (RentCafe, 2023). Knowing these ranges helps set realistic expectations for renovation scope and material budgets.

Room-level data is equally important. A standard two-car garage is 400–576 sq ft (20 × 20 to 24 × 24), a master bedroom averages 200–350 sq ft, and a single-car garage runs 200–260 sq ft. Kitchens in new-construction homes average 160–200 sq ft, not counting open-concept living areas.

*Sizes based on 2023 NAHB and Census Bureau data
SpaceTypical Size (sq ft)Notes
Studio apartment400–600No separate bedroom
Master bedroom200–350Includes walk-in closet area
Standard bedroom120–180Fits queen bed + dresser
Kitchen160–200New-construction average
Two-car garage400–57620×20 to 24×24 ft
Full bathroom40–60Tub, toilet, vanity
4

Converting Square Feet to Other Units

Real estate transactions in the US use square feet, but carpet is sold by the square yard (1 sq yd = 9 sq ft), land is measured in acres (1 acre = 43,560 sq ft), and international listings use square meters (1 sq m = 10.764 sq ft). A 1,800 sq ft home equals roughly 167 sq m or 200 sq yd.

Conversions become critical when comparing import tile priced per sq m against domestic tile priced per sq ft. A tile listed at $45/sq m equals $4.18/sq ft — easy to misjudge without converting first. Always convert to a single unit before comparing costs.

  • Sq ft to sq yards — divide by 9 (flooring, carpet)
  • Sq ft to sq meters — multiply by 0.0929 (international listings)
  • Sq ft to acres — divide by 43,560 (land, lots)
  • Sq meters to sq ft — multiply by 10.764 (import materials)
  • Hectare to sq ft — multiply by 107,639 (agricultural land)
5

Measuring Square Footage for Material Orders

Ordering materials based on raw square footage leads to shortfalls. The industry standard is 10% waste for simple rectangular rooms, 15% for diagonal tile patterns or rooms with many cuts, and 20% for herringbone or complex layouts. A 300 sq ft room with diagonal tile needs 345 sq ft of material.

Flooring is sold in boxes of 20–25 sq ft; always round up to full boxes. Paint covers 350–400 sq ft per gallon, so a 432 sq ft wall needs 1.1–1.2 gallons per coat — buy 2 gallons for two coats. Concrete requires area plus depth: a 10 × 10 ft patio at 4” thick needs 1.23 cubic yards.

  1. 1

    Sketch the floor plan

    Draw each room on graph paper or a digital tool, labeling lengths to the nearest inch.

  2. 2

    Break into simple shapes

    Split L-shapes, bay windows, and alcoves into rectangles, circles, or triangles.

  3. 3

    Calculate each area

    Use Length × Width for rectangles, πr² for circles, ½ × Base × Height for triangles.

  4. 4

    Sum and add waste

    Total all areas, then add 10–20% depending on layout complexity and material type.

  5. 5

    Convert to purchase units

    Divide by coverage per unit (sq ft per box, per gallon, or per cubic yard) and round up.

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Last Updated: Mar 26, 2026

This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.

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