Square Footage Calculator Multiple Rooms. Square Footage Calculator Multiple Rooms: Calculate square footage for multiple rooms at once. Add room areas together for total floor space. Perfect for.

Precision Calculator

Square Footage Calculator Multiple Rooms

Square Footage Calculator Multiple Rooms: Calculate square footage for multiple rooms at once. Add room areas together for total floor space. Perfect

Room Dimensions

Material Waste FactorOptional

Estimate Material CostOptional

Calculation Results

What is a square foot?

1 ft (12 in) 1 ft 1 ft² = 144 in²

A square foot (sq ft) is a measurement of two-dimensional area. One square foot equals a square that is 1 foot (12 inches) long on each side. It is the standard measurement unit used for assessing property dimensions, room sizes, and estimating material coverage like flooring, paint, and landscaping.

How to Calculate Square Footage

12 ft 10 ft Area 120 ft²

To calculate square footage, measure the length and width of your space in feet and multiply those two numbers together. This calculation provides the total area square footage.

Example Calculation

A room is 12 feet long and 10 feet wide. Multiply 12 by 10 to get 120. There are 120 square feet in the room.

Basic Formula for Area

L × W = Area ft²

The basic formula for area is Length × Width. Measure both the length and width in the same unit before multiplying.

Basic Length Conversion

There are 3 main length conversions you need for area measurement:

  • Inches to feet: Divide the number of inches by 12.
  • Yards to feet: Multiply the number of yards by 3.
  • Meters to feet: Multiply the number of meters by 3.28084.

Area Conversion

1,000 ft² Square Feet 144,000 in² 111.11 yd² 92.90 m² 0.023 acres

There are 4 common area conversions used in construction estimation:

  • To convert square inches to square feet, divide by 144.
  • To convert square yards to square feet, multiply by 9.
  • To convert square meters to square feet, multiply by 10.7639.
  • To convert acres to square feet, multiply by 43,560.

Use our Area Conversion Calculator tool above to automate these conversions.

Area Formulas for Different Shapes

Square Rectangle Circle Triangle Trapezoid L-Room Wall Annulus

There are 13 geometric shapes supported by the Square Footage Calculator. Below are the specific formulas for estimating area.

Square Shape

Square Side (a) Side (a)

Calculate square footage of a square

Formula: Side Length × Side Length. Measure one side of the square and multiply it by itself.

Rectangle Shape

Rectangle Length (l) Width (w)

Calculate square footage of a rectangle

Formula: Length × Width. Measure the long side and the short side, then multiply them.

Rectangle Border Shape

Rectangle Border

Calculate square footage of a rectangle border

Formula: Total Area (Outer Length × Outer Width) − Inner Area (Inner Length × Inner Width). Calculate the large outer rectangle area, then subtract the smaller inner rectangle area.

Wall and Window Shape

Wall with Window

Calculate square footage of a wall minus window

Formula: Wall Area (Wall Height × Wall Width) − Window Area (Window Height × Window Width). This reveals the exact paint or drywall coverage needed.

Cathedral Wall

Cathedral Wall

Calculate square footage of a cathedral wall (right trapezoid)

Formula: ½ × Base Width × (Left Wall Height + Right Wall Height). This calculates sloped ceiling walls.

Circle Shape

r Circle

Calculate square footage of a circle

Formula: π × Radius². Measure the distance from the center to the edge (radius), square it, and multiply by 3.14159.

Circle Border Shape

Annulus / Border

Calculate square footage of a circle border

Formula: π × (Outer Radius²) − π × (Inner Radius²). Subtract the inner circle area from the outer circle area.

Annulus Shape

Annulus / Border

Calculate square footage of an annulus

Formula: π × (Outer Radius² − Inner Radius²). This is the mathematical term for a ring or circle border.

Triangle Shape

Base (b) Triangle

Calculate square footage of a triangle

Formula (Heron's): √[s(s-a)(s-b)(s-c)], where 's' is half the perimeter. Measure all 3 sides when you do not know the height.

Triangle Shape (Base & Height)

h Base (b) Triangle

Calculate square footage of a triangle using base and height

Formula: ½ × Base × Height. Measure the bottom length and the straight vertical height.

Trapezoid Shape

h Top (a) Base (b) Trapezoid

Calculate square footage of a trapezoid

Formula: ½ × (Base A + Base B) × Height. Add the parallel sides, multiply by the straight height, and divide by 2.

Sector

θ r Sector

Formula: ½ × Radius² × Angle (in radians). This calculates a specific wedge of a circle.

Parallelogram

h Base (b) Parallelogram

Formula: Base × Height. Multiply the bottom length by the vertical height.

Calculations for 'L' Shaped Rooms or Areas

A₁ = 180 × 80 A₂ = 100 × 100 10 ft Total Area A₁ + A₂

Split an irregular shape or L-shaped room into two distinct rectangular sections. Calculate the square footage of each section separately using Length × Width, then add the two results together.

Example Calculation

Section A is 10 ft by 5 ft (50 sq ft). Section B is 6 ft by 4 ft (24 sq ft). The total is 74 square feet.

Calculating Square Footage for Walls

Wall Width Height W × H − windows − doors

Measure the wall width and the wall height in feet. Multiply the width by the height. Subtract the area of any doors or windows to find the exact paint coverage required.

Calculating the Square Footage of a House or Property

Living Room 250 ft² Kitchen 180 ft² Bedroom 200 ft² Bathroom 50 ft²

Measure the length and width of every rectangular room inside the building. Calculate the area for each room, then add the totals together. Exclude unfinished basements and garages from standard real estate square footage.

Adding Surplus for Materials

Usable material Waste (~10%)

Construction projects require purchasing 5% to 15% more material than the exact calculated area to account for cutting, mistakes, and material waste factor. Use our material waste toggle in the calculator tool to add this surplus automatically.

Waste Percentages by Material Type

There are 3 standard waste percentages for construction materials:

  • Hardwood flooring: Add 5% for standard rooms, 10% for diagonal layouts.
  • Tile projects: Add 10% to 15% for complex patterns and breakage.
  • Paint: Add 10% for spillage and touch-ups.

Calculating Cost Per Square Foot

Area 120 ft² × Price $3/ft² = Total $360

Divide the total project cost by the total square footage. For example, a $1,000 project covering 200 sq ft costs $5 per square foot.

Painting a House

Measure the height and width of all exterior walls. Subtract the windows and doors. Multiply the remaining square footage by the paint coverage rate (usually 350 sq ft per gallon).

Flooring Installation

Calculate the floor area square footage and add a 10% waste factor. Multiply this total by the price per square foot of your flooring material.

Building a Home

Multiply the architectural floor plan area by the regional building cost per square foot to estimate total construction costs.

Calculate Cost of Materials

Tile $2/ft² Wood $5/ft² Carpet $7/ft² Marble $12/ft²

Use the Material Cost toggle in our calculator. Input the price per unit and the currency. The calculator will multiply the final project area (including any waste percentage) by the material cost.

How to Use the Square Footage Calculator

1 Shape 2 Dims 3 Result Select Shape Enter Dimensions Get Area + Cost

Select your shape from the dropdown menu. Input the length, width, or required dimensions into the fields. Set your desired measurement units. The calculator automatically computes the square footage online.

How to Calculate Square Footage Pricing

Calculate your total area footprint, add your waste factor margin, and multiply the final square footage by the contractor or material rate per square foot.

Calculate square footage (sq ft) from other units

Input your measurements into our tool using yards, meters, or inches. The calculator engine automatically converts these inputs and outputs the result in square feet.

How do I convert square meters to square feet?

Multiply the area in square meters by 10.7639 to get square feet.

How do I convert acres to sq ft?

Multiply the number of acres by 43,560 to get square feet.

Final Remarks About Square Footage

Accurate space estimation and precise layout calculation prevent material shortages and budget overruns. Whenever estimating bulk materials like mulch or gravel, calculate the area first, then calculate Volume to Cubic Yards.

How It Works

1

Select Shape

Choose from 13 shapes including rooms, walls, circles, triangles, and more.

2

Enter Dimensions

Input measurements in any unit. Add quantity, waste factor, and material price.

3

Get Results

View area in ft², in², yd², m², acres plus cost estimate — all at once.

Frequently Asked Questions

Measure each room individually (length × width), then add all the areas together. With this calculator, you can use the Quantity field to multiply identical rooms, or calculate each room separately and sum the results.
For flooring projects, yes — hallways need flooring too. Measure each hallway as a separate rectangle (length × width). For room-only calculations like painting individual rooms, you can exclude hallways.
Measure all rooms, hallways, and closets that need flooring. Add the areas together, then add 5–15% waste factor for cuts and fitting. Use the Material Waste Factor field in the calculator to include this automatically.
Yes. Calculate the square footage of each room individually using this calculator, note down each result, and add them manually. All rooms contribute to the total regardless of their individual dimensions.
Calculate each room separately and apply different waste percentages and material costs for each. For example, tile in the kitchen (10–15% waste) and hardwood in the living room (5–10% waste) should be estimated independently.
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