Square Footage Calculator
Total up the floor area of one room or a whole loft from length × width — in square feet and square metres, from measurements in inches, feet, or metres.
Total floor area
Each room’s area is length × width; add every rectangular space to get the whole floor. For an L-shaped room, split it into rectangles and add them as separate rooms.
Why floor area is the first number to know
Square footage is the figure everything else in a home hangs off. It tells you how much flooring to order, what a space is worth per square foot, how many people a room comfortably seats, and whether a sofa or a kitchen island will actually fit. In a loft or small apartment, where every square foot is working hard, getting it right is the difference between a plan that fits and one that doesn’t.
The maths is simple — length times width for each rectangle — but adding up several rooms by hand is where small errors creep in. Measure each rectangular area, add them here, and read the total in whichever unit your flooring or furniture is sold in.
Frequently Asked Questions
How do I calculate the square footage of a room?
Measure the room's length and width, then multiply them: a 12 ft × 10 ft room is 120 square feet. This calculator does that for each room you add and totals them, so you can size a single room or a whole open-plan floor in one go.
Can I mix inches, feet, and metres?
Pick one unit for a given calculation. The calculator converts whatever unit you choose — inches, feet, or metres — into a consistent area and reports the total in both square feet and square metres, so you can measure in the units you have to hand.
How do I handle an L-shaped or open-plan loft?
Split the space into rectangles, measure each one, and add them as separate rooms. The calculator sums them, which is exactly how you'd break down an L-shaped studio or a kitchen-diner that flows into a living area.
How do I convert square feet to square metres?
One square foot is about 0.0929 square metres, so a 120 sq ft room is roughly 11.15 m². The calculator shows both figures automatically so you don't have to convert by hand.
Does this measure floor area or wall area?
This is floor area — the footprint you'd carpet, tile, or furnish. For painting you want wall area instead, which the paint calculator derives from the room's perimeter and ceiling height.
Estimates for planning — not professional real-estate, architecture, or financial advice. For a sale, mortgage, or building work, use a measured survey.