L-Shaped Room Calculator: Square Feet and Flooring Cartons
Split your L-shaped room into two adjoining rectangles, enter their dimensions in feet, and see the total floor area. The diagram shows the split so that no area is counted twice.
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Planning estimate. Use actual product coverage and check the cutting layout before ordering.
How the calculation works
Total area = (A width × A depth) + (B width × B depth). The rectangles share an edge and do not overlap. This layout assumes that their lower edges line up. A mirrored L has the same area. If both depths match, the shape is a rectangle.
Add the allowance once to the combined area, then divide by the coverage printed on the carton and round up to a whole carton. The example 12 × 10 plus 6 × 5 gives 150 sq ft; 10% extra gives 165 sq ft; at 24 sq ft per carton, buy 7 cartons covering 168 sq ft.
Use your area for the next step
- Estimate tile pieces and boxes — enter the net room area; apply the allowance once.
- Estimate laminate cartons — enter the dimensions for a rectangle or use your combined area to plan the purchase.
- Estimate the flooring material budget — use 150 sq ft as net area in the worked example.
Feet, inches and awkward corners
Convert inches to a fraction of a foot: 12 ft 6 in = 12.5 ft. Measure at the floor, include closets that will receive flooring, and split alcoves into separate rectangles. This two-part calculator does not deduct holes, curved edges, columns or stair openings; handle those on your sketch before ordering.
Reviewed October 5, 2026. Measurements and examples are for planning; product specifications and the actual installation layout control the order. See our calculation methods and product sources.