Tile: how many tiles, and how much grout and thinset
Tile is counted from the area divided by the size of one tile plus its grout joint, with extra for cuts and breakage. 100 square feet of 12 x 12 inch tile is 108 tiles, or 11 boxes of 10, with 10% extra, and it takes 2 bags of thinset and about 7.8 lb of grout at a 1/8 inch joint.
Below is everything we have on tiling: the tile and full-project calculators, the guides to grout, thinset and floor tile, heated floors under tile, and the mistakes that show up only once the grout is dry.
Tiles by area and tile size
With a 1/8 inch joint and 10% extra for cuts. Worked out by the tile calculator.
| Area (sq ft) | 12 x 12 in | 12 x 24 in | 18 x 18 in | 6 x 24 in plank |
|---|---|---|---|---|
| 25 | 27 | 14 | 13 | 27 |
| 50 | 54 | 28 | 25 | 54 |
| 75 | 81 | 41 | 37 | 81 |
| 100 | 108 | 55 | 49 | 108 |
| 150 | 162 | 82 | 73 | 161 |
| 200 | 216 | 109 | 97 | 215 |
Tiles, grout and thinset
Larger tiles need a bigger trowel notch and so more thinset per square foot; narrower joints and thinner tiles need less grout. The tile calculator works out all three together from the tile size, joint width and notch.
The full list for a bathroom or kitchen floor
A tiled floor also needs cement backer board (or a membrane), screws, spacers and the tools. For an 8 x 5 ft bathroom floor in 12 inch tile the project calculator lists 44 tiles in 5 boxes, 3 sheets of backer board and 1 bag of thinset.
Finishing: caulk, countertops and heated floors
Where tile meets a tub, a counter or a change of plane, caulk goes in instead of grout. If you are adding electric floor heat under the tile, size the mat and its circuit before you buy the tile, because the mat goes down first.
Every calculator for this topic
Guides
- Common Mistakes When Tiling a Floor (Waste, Boxes, Grout)Tile mistakes that cost a second trip to the store. A 12 × 10 ft floor of 12 in tile needs 130 tiles with 10% extra, 136 with 15%.
- How Many Tiles Do I Need? Tiles per Square Foot and by Room SizeA 12 × 10 ft floor of 12 inch tiles takes 130 tiles with 10% waste, 13 boxes of 10, plus 2 bags of thinset. Tiles per sq ft for each size, and the waste to add.
- How Many Tubes of Caulk Do I Need? Feet per Tube by Bead SizeA standard 10.1 oz tube of caulk fills about 24 feet of a 1/4 × 1/4 inch joint. A chart of feet per tube by bead size, and the tubes for 40 and 100 feet.
- Electric Floor Heating: Watts per Square Foot and Cost to RunElectric floor heating needs about 12 watts per square foot. A chart of watts, amps, breaker and running cost for bathrooms and rooms, and how to install it.
- How Many Square Feet of Countertop? Slabs for L-Shaped KitchensCountertop area = length × depth. A chart for straight, L-shaped and U-shaped runs, islands and backsplash, with how many quartz or granite slabs to order.
- Bathroom Floor Tile Materials List: Tile, Thinset, Grout, BackerWhat to buy to tile a 5×8 ft bathroom floor: tiles and boxes, thinset, grout, cement board, spacers and tools, with quantities and a chart for other floors.
- How Much Tile, Grout and Thinset Do I Need? Coverage GuideEstimate tiles, boxes, bags of thinset and pounds of grout for a floor, shower or backsplash, with waste factors by layout and grout by tile size.
Other guides that use these calculators: How Much Paint to Paint the Outside of a House (Size Chart) · How Much Flooring Do I Need? Boxes by Room Size and Waste · Paint Sheen Guide: Flat, Eggshell, Satin or Semi-Gloss? · Exterior House Painting Materials List: Paint, Primer and Prep · Painting a Room Materials List: Paint, Primer, Tape and Supplies · Waste Factors Cheat Sheet: How Much Extra Material to Buy
Answers for common sizes
Already know the size? These pages give the worked answer for one common size each, with the inputs filled in so you can adjust them.
Project planners
Planning the whole job rather than one material? These step-by-step planners put the calculators above in the order you will need them.
Frequently asked questions
How many tiles do I need for 100 square feet?
108 tiles of 12 x 12 inches with a 1/8 inch joint and 10% extra, which is 11 boxes of 10.
How much extra tile should I buy?
Ten percent for a straight layout in an ordinary room, and 15% for diagonal or herringbone patterns or large-format tile that breaks easily. Keep a few spares for repairs.
How much grout do I need?
It depends on tile size, joint width and tile thickness. For 100 square feet of 12 inch tile at a 1/8 inch joint, about 7.8 lb.
Can I tile straight onto plywood?
Not directly for most floor tile: use cement backer board or an uncoupling membrane over a stiff subfloor, as the tile and membrane makers specify.
Related topics
Estimates only. Quantities depend on your materials, site and supplier, so check coverage and sizes on the label. Follow local building codes for anything structural. How we calculate.