How to measure a room for flooring

What you need

A tape measure (a 25 ft tape is fine for most rooms), graph paper or your phone, and a pencil. Measure in feet and inches, then convert to decimal feet — 12 ft 6 in is 12.5 ft.

Step 1: Sketch the room

Draw a rough floor plan including closets, alcoves, bay windows and doorways. Mark which closets get the new floor and where the flooring will transition to other rooms.

Step 2: Measure wall to wall

• Measure at floor level, from wall to wall, in the longest direction and then the widest.
• Measure in two or three places — walls are rarely perfectly parallel. Use the largest measurement.
• Don't deduct for baseboards; they come off or cover the expansion gap.

Step 3: Break odd shapes into rectangles

An L-shaped room is two rectangles; a closet is its own small rectangle; a bay is a trapezoid. Work out each area and add them up — the square footage calculator lets you enter each piece on its own row.

Step 4: Decide the layout direction

Planks usually run parallel to the longest wall or toward the main light source, and continuous through doorways into connected rooms. Running planks diagonally or in herringbone looks great but increases waste — plan 15% or more instead of 10%.

Step 5: Add waste and round up to boxes

Divide the total by the coverage per box printed on the carton and round up. The flooring calculator does this and adds underlayment and trim; for tile, use the tile calculator, which accounts for grout joints.

Step 6: Don't forget the extras

• Underlayment (unless it's attached to the planks) and a vapor barrier over concrete where the manufacturer requires it.
• Transitions and thresholds at doorways and where the floor meets other materials.
• Baseboard or quarter round for the perimeter, minus doorways.
• A spare box from the same lot for future repairs.

Frequently asked questions