Square Footage Calculator
Multiply length by width to find the area of a room, floor, or plot — in square feet and square metres.
Feet in, area out
Enter length and width in feet and the calculator returns the area in square feet, with the metric equivalent beside it.
Rectangles only
The formula assumes a straight-sided rectangle. Split irregular spaces into rectangles and add the parts together.
What is square footage?
Area measured in square feet
Square footage is the area of a flat, rectangular surface measured in square feet — the standard way to size rooms, flooring, lawns, and building plots in countries that use imperial units. It answers a simple question: how much surface does this space cover? Knowing it lets you buy the right amount of flooring, paint, or turf, and compare spaces on a common scale.
Multiply the length by the width, then multiply by the number of identical areas you are measuring.
Area = length × width × number of areasBecause area is length times width, the units multiply too: feet × feet gives square feet. The "number of areas" field is a shortcut for totalling several identical rectangles at once — leave it at 1 for a single space.
Suppose you are measuring a bedroom that is 12 feet long and 10 feet wide.
Multiply length by width
12 × 10 = 120 square feet for one room.Account for how many
With one room, 120 × 1 = 120 square feet.Convert to metric
120 × 0.0929 ≈ 11.15 square metres.
The headline figure is the surface area you would need to cover. Read it in context: a flooring or paint estimate usually adds 5–10% for waste and offcuts, so round up rather than down. The square-metre figure is the same area in metric units — 1 square foot equals 0.0929 square metres — handy when product packaging or a contractor quotes in metres. For an L-shaped or stepped space, add up the rectangles: split the floor into straight-sided pieces, find each one's square footage, and total them.
The arithmetic is exact, but it only describes one shape.
Straight-sided rectangles only
This calculator multiplies length by width, which is correct only for a rectangle. Curved walls, triangles, and circular areas need their own formulas, and irregular rooms should be broken into rectangles and summed. Always measure to the inside faces of the walls for an interior floor area, and keep length and width in the same unit (feet) before entering them.