Toolnido

Tile Calculator with Grout and Thinset: How Much Should You Buy?

Enter the surface, tile size and joint width. Get tiles with waste, boxes, grout bags and thinset bags in one buy list, plus a to-scale layout drawing. Feet or metres. Runs in your browser.

When to use this

How to use

  1. Choose feet or metres. Enter the length and width of the surface and any area that will not be tiled.
  2. Enter the tile size, the joint width and the joint depth (normally the tile thickness).
  3. Set the waste percentage and, if you know it, the number of tiles per box.
  4. Pick the grout bag size and the trowel notch, or type the coverage printed on your thinset bag.
  5. Press Calculate tile. Check the buy list, then copy it or download the drawing.
Units
Surface to tile

A floor, or a wall measured as width by height. One flat rectangle per calculation.

Tub, vanity, window or door openings. Add their areas together. 0 if none.

Tile and joints

1/8 in is 0.125 in or about 3 mm.

Usually the tile thickness. 3/8 in is 0.375 in or about 10 mm.

10 is common; 15 for diagonal layouts or small rooms.

Leave blank to skip the box count.

Grout and thinset

Read it on your bag. The built-in values are UNSOURCED. Changing it switches the notch to Custom.

Examples

Understanding the result

Tiles are counted on a grid of tile plus joint, then the waste percentage is added and the total is rounded up to whole tiles and whole boxes. Grout is the volume of the gap around one tile (joint width x joint depth x the tile's two sides plus the joint) times the number of tiles, turned into weight with a built-in powder density and a 10 percent spare. Thinset is the area divided by the coverage of one bag, with the same spare.

Limitations

FAQ

How many tiles do I need for a room?

Divide the area to tile by the area of one tile plus its joint, then add waste and round up. This tool does that, shows the boxes if you give tiles per box, and draws the grid.

How much waste should I add for tile?

About 10 percent is a common starting point for straight layouts. Diagonal layouts, small rooms and many cuts often use 15 percent. Extra tiles also cover future repairs.

How much grout do I need?

It depends on the tile size, joint width and joint depth. Small tiles and wide, deep joints use much more. The tool uses the volume of the gap around each tile and a built-in powder density, so check the coverage chart on your grout bag.

How much thinset do I need?

Thinset bags list a coverage for each trowel notch. Bigger notches use more per square foot. The presets are rough values marked UNSOURCED, so type the coverage from your bag if you can.

Should I subtract the area of a tub or window?

Yes, enter large openings as area not tiled. Small openings can be ignored because the cut tiles around them take the same waste you already added.

Does this tool store my measurements?

No. It runs in your browser. The share link keeps your numbers after the # sign, which is never sent to a server.

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