Room Size Calculator: Area, Perimeter & Square Footage
Work out the area and perimeter of any rectangular room, in square feet and square metres. Use it before buying flooring, paint, rugs or furniture, so you know the size you are working with.
How this calculator works
Area is length multiplied by width. Perimeter is 2 x (length + width). One square foot is 0.092903 square metres, and one foot is 0.3048 metres. For an L-shaped room, split it into two rectangles, calculate each one, and add the areas together.
Related guide: Small Living Room Ideas That Make the Room Feel Bigger
Frequently asked questions
How do I calculate the square footage of a room?
Multiply the length by the width, both in feet. A room 15 feet by 12 feet is 180 square feet.
How do I convert square feet to square metres?
Multiply square feet by 0.092903. A room of 180 square feet is about 16.7 square metres.
How do I measure an L-shaped room?
Split it into two rectangles, calculate the area of each, and add them together.
What is perimeter used for?
Perimeter is used for skirting boards, coving, wallpaper borders, and estimating the length of trim or edging you need.