Tile Estimator

Mosaic Tile Calculator

How much tile do you need? You’ll know in just 4 quick steps . . .

1. Measure Your Surface

Measure the dimensions of the surface you would like to mosaic and calculate the area using the formulas from elementary school:

• RECTANGLE AREA = length x width
• TRIANGLE AREA = 1/2 x width x height
• CIRCLE AREA = 0.785 x diameter x diameter

Keep in mind that 1 ft² is 144 in².

If you get your answer in square inches, just divide by 144 to get the answer in square feet.

We have help with the formulas at the bottom of the page if you need it.

2.  Look Up An Estimate

Now look up an estimate of the number of mosaic tiles you need based on square footage. Except for 8mm and 3/8 inch tile, these estimates assume a grout spacing of 1/16 inch between the tiles. The 8mm and 3/8 inch numbers are based on a smaller grout gap of 1/32 inch. The first three columns refer to mosaic marble stone of different types. The fourth column refers to 3/4-inch glass mosaic tile. Remember that 1 ft² is 144 in².

Mosaic Area	8mm (5/16″)	10mm (3/8″)	12mm (1/2″)	15mm (9/16″)	20mm (3/4″)
1 ft²	1225	872	508	369	218
2 ft²	2450	1744	1016	737	436
3 ft²	3675	2616	1524	1106	654
4 ft²	4900	3488	2032	1475	873
5 ft²	6125	4360	2540	1843	1091
6 ft²	7350	5232	3048	2212	1309
7 ft²	8575	6104	3556	2580	1527
8 ft²	9800	6976	4064	2949	1745
9 ft²	11025	7848	4572	3318	1963
10 ft²	12250	8720	5080	3686	2181

3. Are you cutting the tiles?

Cutting a mosaic tile in pieces theoretically decreases the amount of tile you need. How is this so? You will have more pieces, so there will be more grout lines in the mosaic. More grout lines means more grout and less mosaic tile. The effect can be significant. For example, it requires 218 of the 3/4″ glass mosaic tiles to cover 1 square foot with a grout spacing of about 1/16 inch, but if you cut the tiles into pieces, you might only need 200 tiles. On the other hand, people who cut tile probably should budget a little extra as waste. That’s why we use 218 per square foot as a rule of thumb for 3/4″ mosaic tile.

4. Consider the Spacing Between Tiles

Tile coverage is determined as much by the grout spacing between the tiles as it is by the area you are covering. All of the calculations in our tables assume a standard grout spacing for that particular size. Grout gaps of standard size ensure that grout penetrates between the tiles and covers the adhesive underneath, while the hairline crack between “touching” tiles can never be grouted reliably. Standard size grout gaps are also optimal for aesthetic reasons, while using no grout gap between tiles of similar color does not look like distinct pieces at a distance. For advice about choosing a grout color, see our page of Mosaic Instructions.

Note that 3/4″ glass mosaic tile sometimes comes face-mounted on paper so that the installer can glue the whole sheet to a wall and then peel the paper off the face of the tile and then grout. These sheets are made according to metric standards, so that the grout spacing is slightly larger than 1/16″. Typically there are 225 tiles mounted on a sheet that is 1.15 square feet. Our metallic glass mosaic tiles and swirled glass mosaic tiles are cut from such sheets. Most artists remove the tiles from the sheets before using, so this doesn’t matter.

Help with the Formulas