面积计算器

Square Footage Calculator: Calculate Square Feet Easily

Calculating the size of a room, house, floor, or any other space can be confusing if you are not familiar with measurements and area formulas. A square footage calculator makes this process simple by helping you quickly determine the total area of a space in square feet.

Whether you are planning a home renovation, buying flooring, estimating paint requirements, comparing property sizes, or working on a construction project, knowing the exact square footage helps you make better decisions and avoid costly mistakes.

The calculator above lets you enter measurements such as length and width to work out the area accurately. You can use it for rooms, houses, floors, land areas, and other spaces where you need to determine square footage.

What a square footage calculator does

A square footage calculator is a simple tool used to find the total area of a space by using its measurements. In most cases, you only need two basic dimensions:

• Length of the area
• Width of the area

The calculator applies the square footage formula automatically and provides the total area in square feet. For a room 12 feet long and 10 feet wide:

12 × 10 = 120 square feet

A square feet calculator is useful for homeowners, contractors, designers, real estate professionals, and anyone who needs a quick and accurate square footage calculation.

Square footage refers to the amount of surface area covered by a space. It is commonly used in:

• Home measurements
• Real estate listings
• Flooring installation
• Construction projects
• Landscaping
• Interior design
• Material estimation

For example, before installing new flooring, you need to know the total floor area. Before painting walls, you need accurate measurements to estimate paint coverage. In both situations, calculating square footage provides a reliable starting point.

How to calculate square footage

Learning how to calculate square footage is simple once you understand the basic measurement process. The most common formula is:

Length × Width = Square Feet

To calculate the area of a rectangular or square space:

1. Measure the length of the area in feet.
2. Measure the width of the area in feet.
3. Multiply both measurements together.
4. The result is the total square footage.

Example: calculating a room area

Suppose you have a bedroom 15 feet long and 12 feet wide:

15 × 12 = 180 square feet

This method works for most common spaces, including bedrooms, kitchens, offices, garages and living rooms.

The square footage formula explained

The square footage formula depends on the shape of the area you want to measure. While most rooms are rectangular, some spaces require different calculations.

Rectangle and square

Area = Length × Width

A square room with 10 feet on each side:

10 × 10 = 100 square feet

圆形

Area = π × Radius²

Where π is approximately 3.14 and the radius is the distance from the centre of the circle to the edge. This formula is useful for calculating circular patios, gardens, or other round spaces.

三角形

Area = (Base × Height) ÷ 2

This calculation can help measure uniquely shaped spaces where a triangle section needs to be included.

For complex spaces, divide the area into smaller sections, calculate each section separately, and then add the results together to find the total square footage.

How to measure the square footage of a room

Room measurements are one of the most common uses of square footage calculations.

Step 1: Measure the length

Use a measuring tape to find the distance from one wall to the opposite wall.

Step 2: Measure the width

Measure the other side of the room from wall to wall.

Step 3: Multiply the measurements

Length × Width = Room Area

For a room measuring 14 feet by 11 feet:

14 × 11 = 154 square feet

If your room has unusual sections, divide it into smaller rectangles, calculate each section separately, and add them together. The calculator above makes this faster by working out the total once you enter your measurements.

How to calculate the square footage of a house

Many people want to know the size of their house when buying, selling, renovating or planning improvements. Calculating the square footage of a house involves measuring each usable area and adding them together:

• Measuring individual rooms
• Calculating each room area
• Adding all room measurements
• Including hallways and other usable spaces

Bedroom: 150 sq ft
Kitchen: 120 sq ft
Living room: 250 sq ft
150 + 120 + 250 = 520 square feet

Keep in mind that different property measurement standards may exclude areas such as unfinished basements, garages or outdoor spaces, depending on local rules.

Square footage conversion guide

Measurements are not always provided in feet. Sometimes you may need to convert inches, yards or metres into square feet before calculating an area.

Convert square inches to square feet

Square inches ÷ 144 = Square feet

1,440 ÷ 144 = 10 square feet

Convert inches to square feet

1. Convert inches into feet by dividing by 12.
2. Multiply length by width.

A space measuring 120 inches by 96 inches:

120 ÷ 12 = 10 feet
96 ÷ 12 = 8 feet
10 × 8 = 80 square feet

This method helps when working with smaller measurements like furniture areas, tiles or flooring sections.

Common uses of square footage calculation

Flooring installation

Before buying tiles, hardwood, carpet or vinyl flooring, you need the exact floor area. Accurate measurements help estimate the amount of material required and reduce waste.

Painting projects

Square footage helps estimate paint coverage. Contractors usually calculate wall areas separately, because doors and windows may reduce the amount of paint needed.

Construction planning

Builders use floor area calculations to estimate materials, project costs and space requirements.

Real estate

Property listings commonly display house square footage because it helps buyers compare homes and understand the available living space.

Landscaping projects

Square footage calculations are useful for gardens, patios, lawns and outdoor improvement projects.

Common mistakes when measuring square feet

Measuring incorrectly

Always measure from wall to wall and double-check your numbers before calculating.

Mixing different units

Do not combine inches, feet and metres in the same calculation. Convert all measurements into the same unit first.

Forgetting irregular areas

Rooms with corners, extensions or unusual layouts require dividing the space into smaller sections.

Ignoring waste materials

For projects like flooring and tiles, allow for additional material for cutting and installation waste.