Room Square Footage Calculator

By Vinod Kondeti · Updated October 14, 2026

Most rooms are not perfect rectangles. Closets, bay windows and L-shapes add area. Split the floor into up to three rectangles, enter each one, and the calculator adds them up. Set unused sections to 0.

Main area length (ft)Main area width (ft)Section 2 length (ft)Section 2 width (ft)Section 3 length (ft)Section 3 width (ft)Subtract: length (e.g. island) (ft)Subtract: width (ft)

Cost estimate (optional, enter your local prices)

Price per ft² (material or installed) ($)

Square feet	–
Square yards	–
Square meters	–
Acres	–
Estimated cost	–

Working: –

How do I measure for a room project?

Sketch the room and draw lines to cut it into rectangles that do not overlap.
Measure each rectangle on its own, using the same reference wall.
For a closet, include it if you are buying flooring and skip it if you are pricing paint or furniture space.

How is the room amount calculated?

Rectangle: length × width
Circle: π × (diameter ÷ 2)²
Triangle: ½ × base × height
Square yards = ft² ÷ 9; m² = ft² × 0.09290304; acres = ft² ÷ 43,560
Cost = ft² × your price per ft² (flooring: boxes × price per box)

Room calculator questions

How do I find the square footage of an L-shaped room?

Split it into two rectangles and add them. A 14 × 12 main area plus a 6 × 4 nook is 168 + 24 = 192 ft².

Do I measure under cabinets?

For flooring that goes under appliances or islands, yes. For carpet in a kitchen, usually not. Measure what you will actually cover.

Sources

Estimates only. Use the coverage or bag size printed on your product. Read the square footage guide for worked examples.