Tile Calculator

How many tiles, boxes and bags of grout you need.

Project Details
Enter your measurements and requirements
$
Results
Calculated estimates for your project
Area to tile80 sq ft
Tiles (with 10% waste)87
Tile to order87 sq ft
Grout6.4 lb: 1 x 25 lb or 1 x 10 lb
Thinset (50 lb bags)2 with a 1/4 x 3/8 in square notch trowel
Backer board (3 x 5 ft)6 sheets
Tile cost$218
Total materials$399 ($4.98 per sq ft)

How much to buy

Low, 5% waste
83 tiles
Typical, 10% waste
87 tiles
High, 15% waste
91 tiles

Formula: Area / one tile with its grout joint, plus 10% waste, rounded up to whole tiles.

  • Keep one box for future repairs: dye lots change.

Turn these numbers into a build plan.

  • 80 sq ft area
  • 87 @ 12" tiles
  • 2 bags thinset
Materials List
Recommended materials and quantities
Tile, 12 x 12 in87 tiles
Grout, 25 lb1
Thinset, 50 lb2
Cement backer board, 3 x 5 ft6
Spacers1 bag
Trowel1/4 x 3/8 in square notch
darker tiles are cut at the walls. Center the layout so no edge piece is under half a tile.

How we got this: 80 sq ft x 144 / (12 + 0.125) x (12 + 0.125) in per tile = 78.4 tiles, + 10% = 87.

Save this tile plan to Blueprint: the list goes to your phone for the store, the project gets the budget and the demo-to-seal steps, and you can log the box lot number for future repairs and get a reminder to seal the grout once it cures. Comparing with plank vinyl? Try the flooring calculator; renting a wet saw? Check the tool rental calculator.

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Project plan · built from your numbers

Tile a 10 x 8 ft floor (80 sq ft)

Lay 87 12" tiles in a straight (grid) pattern over 80 sq ft, including 10% for cuts and breakage. Covers backer board, layout from center lines, 2 bags of thinset, and grout.

Materials
$417
Time
1 weekend plus 1 evening
Level
Intermediate
7 steps 9 tools 8 materials
  1. 1

    Prep and check the subfloor

    Pull the old flooring and baseboard, then check the 10 x 8 ft floor for flatness. Tile needs about 1/8" in 10 ft or better; grind high spots and fill low ones.

    • Remove old floor, baseboard, and toilet if present
    • Check flatness with a straightedge
    • Fix any squeaks or bouncy joists
  2. 2

    Install backer board

    Lay 6 sheets of cement board over plywood subfloors in a bed of thinset, screw every 8", and tape the seams with mesh. Stagger seams so four corners never meet.

    • Thinset under the board
    • Screw on an 8" grid
    • Tape and skim the seams
  3. 3

    Lay out from the center

    Snap two square center lines and dry-lay a row of 12" tiles with 1/8" spacers both ways. Shift the grid so no wall gets a cut piece under half a tile, especially at the doorway.

    • Snap and square center lines (3-4-5 check)
    • Dry-lay both directions
    • Mark the adjusted starting lines
01 · Your numbers
Area
80 sq ft
Tiles
87 @ 12"
Thinset
2 bags
Est. cost
$417
02 · The plan

7 steps · 9 tools · 8 materials

4 more steps, the full tool list and a shopping list you can check off as you go.

03 · Finished

Your plan is 60% built. Save it.

3/5

Tile a 10 x 8 ft floor (80 sq ft)

Finished in 1 weekend plus 1 evening · $417 DIY

Built for your area of 80 sq ft. Your first plan saves free. No card needed.

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Borrow these 9 tools from neighborsFull how-to guide: Tile a floor or backsplash

Worked example: a 5 x 8 bathroom floor in 12 x 24 tile

40 sq ft. Each 12 x 24 tile with a 1/8 in joint covers 12.125 x 24.125 = 292.5 sq in, about 2.03 sq ft, so 40 / 2.03 = 19.7 tiles. Add 10% for a straight lay: 22 tiles. Grout is about 2.4 lb (one 10 lb bag), thinset 2 bags with a 1/2 x 1/2 in square notch trowel, and 3 sheets of backer board.

  1. Measure the area. Multiply length by width for each area (floor, each shower wall) and add them; subtract the tub, vanity or cabinets.
  2. Find the area per tile. Add the grout joint to each side: (length + joint) x (width + joint) in square inches, divided by 144 for square feet.
  3. Divide and add waste. Tiles = area / area per tile, plus 10% for a straight lay, 15% for diagonal and 20% for herringbone.
  4. Round up to boxes. Divide by the tiles per box on the carton and round up. Buy every box from the same lot number.
  5. Add grout, thinset and backer. Grout from joint width and tile thickness, thinset by trowel notch (about 45 to 60 sq ft per 50 lb bag), and 3 x 5 ft backer board sheets.

Tiles per 100 sq ft by size

With 1/8 in grout joints, before waste
TileTiles per 100 sq ftWith 10% waste
4 x 4 in847932
3 x 6 in subway753829
6 x 6 in384423
12 x 12 in98108
12 x 24 in5056
24 x 24 in2528
6 x 36 in plank6673

Tile waste by pattern

PatternWaste to add
Straight (grid)10%
Offset or brick12%
Diagonal15%
Herringbone20%

Thinset coverage by trowel

TrowelTile sizeSq ft per 50 lb bag
1/4 x 1/4 in square notchUp to 8 in60
1/4 x 3/8 in square notchUp to 15 in45
1/2 x 1/2 in square notchLarge format35

Tile floors need a stiff, flat base: cement backer board over plywood (screw it every 8 in and tape the seams), or an uncoupling membrane. Trim and edge pieces are in the drywall trim calculator; wet saw rental vs buying is in the tool rental calculator; and the tile installation cheat sheet covers layout, setting and grouting. Weighing tile against plank vinyl or laminate? Price both with the flooring calculator.

Tile calculator FAQ

How many tiles do I need for a 10x10 room?

100 sq ft. With 12 x 12 in tile and 1/8 in joints that is 98 tiles, 108 with 10% waste. With 6 x 6 in tile it is 400 tiles, 440 with 10% waste.

How many boxes of tile do I need?

Divide the tiles (with waste) by the tiles per box and round up, or divide the square feet to order by the square feet per box. A box of 12 x 24 tile usually holds 8 tiles, 16 sq ft.

How much grout for 100 sq ft?

About 7.3 lb for 12 x 12 tile with 1/8 in joints, 14.6 lb for 3 x 6 subway, and 14.6 lb with 1/4 in joints. Small tiles and wide joints take far more.

How much extra tile for herringbone?

Order 20% extra (15% for diagonal, 10% for straight). Herringbone cuts a triangle off every tile along each wall.

How do I calculate tile for shower walls?

Measure each wall's width by the tile height (usually to the ceiling or 6 in above the shower head), add the walls, then subtract the window or niche. Enter each wall as an extra area.

What size grout lines should I use?

1/16 in for rectified tile, 1/8 in for most porcelain and ceramic, 3/16 to 1/4 in for stone and handmade tile. Wider joints hide size variation but take more grout.

How much thinset do I need?

A 50 lb bag covers about 60 sq ft with a 1/4 in notch (tiles up to 8 in), 45 sq ft with 1/4 x 3/8 in (up to 15 in) and 35 sq ft with 1/2 in for large format tile, which also needs back-buttering.

Should I use sanded or unsanded grout?

Sanded for joints 1/8 in and wider; unsanded under 1/8 in and on polished marble. Epoxy grout costs more but resists stains and needs no sealer.

Do I need to seal tile and grout?

Seal cement grout and natural stone 48 to 72 hours after grouting. Porcelain and glazed ceramic tile do not need sealing.

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