SuddlTools

Home & garden

Tile calculator: how many tiles do I need?

Enter the size of the floor or wall, your tile size and the grout gap, and pick a waste allowance for your layout. We will count the tiles and boxes, so you buy enough from one batch the first time.

For a backsplash, use its height.
1/8 in is common for floors, 1/16 in for walls.

How to calculate how many tiles you need

Tile quantities come down to two numbers: the area you are covering and the space one tile takes up, including its share of the grout joint. The calculator does the math, but here is how it works so you can double check.

  1. Measure the area. Multiply length by width. A 10 by 12 foot bathroom floor is 120 square feet. For a backsplash, multiply the run of countertop by the height you are tiling.
  2. Size one tile with grout. Add the grout gap to each side measurement. A 12 inch tile with a 1/8 inch joint takes up 12.125 by 12.125 inches, about 147 square inches.
  3. Divide. 120 square feet is 17,280 square inches, and 17,280 divided by 147 is about 118 tiles.
  4. Add waste. Add 10 percent for a straight layout, taking you to 130 tiles, then divide by the tiles per box and round up.

How much extra tile should I buy?

LayoutExtraWhy
Straight or grid10%Cuts along the edges and a few breakages
Brick, offset or staggered15%Every other row starts with a cut tile
Diagonal or herringbone20%Angled cuts at every edge
Large format or natural stone15 to 20%Fewer tiles per cut, more variation to sort through
Keep spare tiles. Store a few unused tiles after the job. Tiles get discontinued and shades change between batches, so a cracked tile years later is easy to swap only if you kept spares.

Choosing a grout gap

Floors usually use a 1/8 inch (3 mm) joint, while wall tiles and backsplashes often go tighter at 1/16 inch (1.5 to 2 mm). Rectified tiles with crisp, machine cut edges can go tighter still, while handmade and rustic tiles need wider joints to hide size differences. The gap makes a real difference to the count on small tiles such as mosaics and subway tiles, so enter the one you plan to use.

Floors, showers and backsplashes

For a shower, measure each wall separately and add them together, then add the floor if you are tiling it too. For a kitchen backsplash, measure the length of each run of countertop and the height to the bottom of the wall cabinets, usually around 18 inches. For flooring in other materials, try the flooring calculator. Find inspiration in our luxury bathroom ideas and small kitchen design ideas.

Frequently asked questions

How many 12x12 tiles do I need for 100 square feet?
About 98 tiles cover 100 square feet with a 1/8 inch grout joint. Add 10 percent for a straight layout and buy around 108 tiles.
How many tiles do I need for a backsplash?
Multiply the length of the countertop runs by the backsplash height, usually 18 inches, then enter that area with your tile size. Subway tile backsplashes often need 15 percent extra for the offset pattern.
Do I include the grout gap when counting tiles?
Yes. Each tile covers its own size plus half the joint on every side. On small tiles like mosaics, leaving the grout out can overestimate how many you need by several percent.
Should I subtract the area of a bathtub or cabinets?
Yes. Tile only goes where it will be seen, so measure around fixed items like tubs, vanities and kitchen islands and leave them out of the area.
Is this tile calculator free?
Yes. It is free, works in imperial or metric and nothing you enter leaves your browser.