SqftKit
SqftKit · Tile

Tile calculator

Tile size, grout joint, waste, then round up

A tile calculator counts pieces, not just square feet. Each tile covers a rectangle, and the grout joint around it is part of the grid you lay out. This tool builds that module from the tile size plus the joint you enter, divides it into the area, applies waste, and rounds up to a whole tile.

Inputs

Result

Enter the area and the tile size.

Disclaimer: This is an estimate for planning. Measure the real space, read the product label, and confirm anything structural, legal, or financial with a qualified person. Nothing you type is sent to a server.

Need the room area first? Use the SqftKit square footage calculator. For mulch or concrete outside, ClearQuip has a mulch calculator and a concrete calculator.

How to use

  1. Measure the surface that will actually get tile. Subtract a hearth or a cabinet only if you have already left it out of the area.
  2. Enter the nominal tile size in inches, as you will space it, not the name on the box if the real tile is smaller.
  3. Enter the grout joint. A joint of 1/8 inch is 0.125. Use 0 if you are butting tiles and the joint is already inside the size you typed.
  4. Set waste and press Calculate. The result rounds up. Reset clears the inputs.

How it's calculated

Module (sq ft) = (tile width + grout) × (tile height + grout) ÷ 144
Tiles = ceiling( area ÷ module × (1 + waste ÷ 100) )

Dividing by 144 converts square inches to square feet. The grout is added once to each side, which matches a layout where every tile owns the joint on its right and bottom, and the perimeter joints are a small extra. That is an ordering model, not a guarantee you will finish with a full tile at the wall.

A kitchen backsplash is usually a short band, so height in inches is easier there. Use the backsplash calculator when the height is not a full wall. Floor tile for a whole room starts from the flooring calculator only if you already know the square feet and do not need a piece count.

Worked example

Fifty square feet of 12 by 12 inch tile with a 1/8 inch joint: the module is 12.125 × 12.125 ÷ 144 = 1.021 sq ft. Raw tiles are 50 ÷ 1.021 ≈ 48.97. With 10 percent waste that is 53.87, and the order rounds up to 54 tiles. Without counting the joint, 50 tiles would look exact and leave you short.

Assumptions and sources

Tile area is ordinary rectangle geometry. Manufacturers publish coverage per carton on the box; this page does not guess a carton size. Large-format tile and diagonal layouts break more pieces, so raise the waste percent rather than trusting 10. Outlets and niches are not auto-deducted.

FAQ

Does the grout joint increase or decrease the tile count?

A wider joint means each tile covers more of the grid, so you need slightly fewer tiles for the same wall. You still buy grout separately; this count is tiles only.

Why did the result round up?

You cannot buy a fraction of a tile. The tool takes the waste-adjusted count and rounds up to the next whole tile.

What if my tiles are sold by the box?

Divide the tile count by the number of tiles per box printed on the carton, then round up to a full box.

Can I use this for a backsplash?

Yes, if you enter the backsplash area in square feet. The backsplash calculator asks for length and height in the units people usually measure a backsplash with.

Related tools