Room Size Calculator

How to Use This Calculator

1. Measure your room's length and width using a tape measure at floor level for accuracy
2. Enter the dimensions in the input fields above
3. Select your preferred measurement unit (feet, inches, meters, or centimeters)
4. Optionally enter the ceiling height for volume calculations useful for HVAC sizing
5. Click "Calculate Room Size" to see results converted to multiple units automatically

For the most accurate measurements, measure at floor level along the walls, not at eye level where walls may be slightly out of plumb.

What is Square Footage?

Square footage is a measurement of two-dimensional area expressed in square feet (sq ft). It represents the total floor space of a room or building and is calculated by multiplying the length by the width. In the United States, square footage is the standard measurement used in real estate listings, construction estimates, and home improvement projects.

Understanding your room's square footage is essential for many practical purposes. When purchasing flooring, carpet, or tile, you need accurate square footage to buy the right amount of material. Paint coverage is calculated per square foot, as is wallpaper. HVAC contractors use square footage combined with volume to size heating and cooling systems properly. Even furniture shopping benefits from knowing your room dimensions to ensure pieces fit comfortably in the space.

How Square Footage is Calculated

The calculation method depends on your room's shape:

• Rectangular rooms: Simply multiply Length x Width to get square footage. This is the most straightforward calculation
• L-shaped rooms: Mentally divide the room into two rectangles, calculate each area separately, then add the results together
• Irregular shapes: Break the room into simple geometric shapes (rectangles, triangles), calculate each area, then sum them
• Rooms with alcoves or closets: Calculate the main room first, then add the alcove areas separately

Understanding Volume Calculations

While square footage measures floor area, cubic footage measures the total volume of space in a room. Volume is calculated by multiplying the floor area by the ceiling height. This measurement is particularly important for:

• Sizing air conditioners and heating systems based on the air volume to be conditioned
• Calculating ventilation requirements for workshops and commercial spaces
• Determining the capacity of storage areas and warehouses
• Meeting building code requirements for minimum room volumes

Conversion Formulas

Square Feet = Length (ft) x Width (ft)

Square Meters = Square Feet x 0.0929

Square Yards = Square Feet / 9

Cubic Feet = Length x Width x Height

Perimeter = 2 x (Length + Width)

Common Room Size References

These typical room sizes help you understand if your measurements seem reasonable:

• Small bedroom: 70-100 sq ft (minimum for single bed)
• Standard bedroom: 120-150 sq ft (comfortable for full/queen bed)
• Master bedroom: 200-350 sq ft (king bed with furniture)
• Living room: 200-400 sq ft (seating for 4-8 people)
• Home office: 100-200 sq ft (desk and storage)
• Bathroom: 40-100 sq ft (full bath with tub)
• One-car garage: 200-250 sq ft (single vehicle)
• Two-car garage: 400-600 sq ft (two vehicles with workspace)

Tips for Accurate Measurements

• Use a steel tape measure for consistent readings over long distances
• Measure wall-to-wall, not just the open floor area
• For carpet or flooring, include closet floors in your measurements
• Take multiple measurements and use the average for precision
• Note any permanent fixtures that reduce usable floor space