How to Measure for Tile

How this calculator works

Step 1 — Sketch the room

Draw the floor plan roughly to scale on paper. Mark every wall, closet, doorway and fixture. You will measure into that sketch rather than trying to hold numbers in your head.

Step 2 — Measure each wall in feet and inches

Measure wall to wall at floor level, not at the baseboard, and take the widest point of each run. Convert inches to decimal feet by dividing by 12: 10 ft 6 in becomes 10.5 ft.

Step 3 — Break the space into rectangles

Worked example: an L-shaped kitchen with a main area of 12 ft × 14 ft and a breakfast nook of 6 ft × 8 ft. That is 168 + 48 = 216 sq ft. A round table area 6 ft across would add π × 3² = 28 sq ft.

Step 4 — Handle walls and openings

For wall tile, multiply width × height and subtract each opening. A 10 ft × 8 ft wall is 80 sq ft; a standard 3 ft × 7 ft door is 21 sq ft and a 3 ft × 5 ft window is 15 sq ft, so you tile 44 sq ft. Do not subtract anything smaller than about 4 sq ft — the offcuts rarely go anywhere useful.

Step 5 — Add waste and convert to boxes

Add 10% for a straight layout, 15% diagonal or hexagon, 20% herringbone, then divide by the coverage printed on the tile box and round up.

Mistakes to avoid

• Measuring to the baseboard instead of the wall.
• Rounding down. Always round every dimension up to the next inch.
• Forgetting the closet, the doorway threshold or under the appliances.
• Ordering in two trips — the second dye lot will not match.
• Trusting the room is square. Check the diagonals before planning a layout.

Next: multi-room square footage calculator, tiles per square foot and the waste factor guide.