How to Measure an L-Shaped Room for Flooring

An L-shaped floor is easiest to measure as two rectangles that meet at one edge. Draw the split first, then label the four dimensions you will enter into the L-shaped room calculator.

1. Sketch the floor you will cover

Mark doorways, closets, alcoves, fixed cabinets and any stair opening. Decide which areas will receive the same flooring. Draw a dividing line from the inside corner of the L to an outside edge; label the two separate pieces A and B. Do not use two full-room rectangles that overlap at the corner.

2. Measure each rectangle at floor level

Record the width and depth of A and the width and depth of B. Measure to the boundaries that will receive flooring, rather than assuming opposite walls are identical. For a visibly uneven room, record several widths and sketch the irregular section separately. Keep all measurements in the same unit.

With a tape marked in feet and inches, divide inches by 12: 10 ft 3 in becomes 10.25 ft. For a 12 ft 6 in by 10 ft 3 in rectangle, the area is 12.5 × 10.25 = 128.125 sq ft. Keep the unrounded area until the final purchasing calculation.

3. Add the areas without overlap

In the diagram, A is 12 × 10 = 120 sq ft and B is 6 × 5 = 30 sq ft. Total floor area is 150 sq ft. Cross-check the outside dimensions: this example fits inside an 18 × 10 rectangle with a 6 × 5 missing corner, so 180 − 30 = 150 sq ft.

4. Apply cuts and carton rounding separately

A 10% example allowance increases 150 sq ft to 165 sq ft. A carton covering 24 sq ft gives 165 ÷ 24 = 6.875 cartons: round up to 7 cartons, or 168 sq ft purchased. The 18 sq ft above the net floor includes 15 sq ft of allowance plus 3 sq ft from carton rounding; it is not a prediction of usable leftovers.

Choose the allowance from the product instructions, pattern, board direction and cutting plan. Ten percent is an example, not a universal rule. Do not add another allowance when carrying an already adjusted area to a second calculator.

5. Check the layout before buying

• Confirm coverage on the exact carton and keep the product and batch consistent.
• Check board direction, transition strips and manufacturer expansion-gap requirements.
• Measure baseboards as a separate linear run; floor area cannot give their length.
• Include only the rooms and closets receiving this product; plan other flooring types separately.

Continue your project

Calculate your L-shaped floor · Calculate laminate cartons · Calculate tile boxes · Build a flooring material budget

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.