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 in^2.  If you get your answer in square inches, just divide by 144 to get the answer in square feet.  

2.  Look Up An Estimate

Now look up an estimate of the number of mosaic tiles you need based on square footage.  These estimates assume a grout spacing of 1/16" between the tiles.  Remember that 1 ft² is 144 in².  The first three columns refer to mosaic marble stone of different types.  The forth column refers to 3/4" glass mosaic tile.

	number 3/8" stones	number 9/16" stones	number 3/8" tiles	number 3/4" tile	sheets iridescent tile
1 ft2	752	369	752	218	10
2 ft2	1505	737	1505	436	20
3 ft2	2257	1106	2257	654	31
4 ft2	3009	1475	3009	873	41
5 ft2	3762	1843	3762	1091	51
6 ft2	4514	2212	4514	1309	61
7 ft2	5266	2580	5266	1527	72
8 ft2	6019	2949	6019	1745	82
9 ft2	6771	3318	6771	1963	92
10 ft2	7523	3686	7523	2181	102

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 grout spacing of 1/16" between the mosaic tiles.  This spacing is common with stone, ceramic and glass mosaic tile because it ensures enough grout will penetrate between the tiles and seal over the adhesive underneath.  It also provides enough gap between the tiles to ensure that the tiles are visually distinct at a distance so that the mosaic does not look like one big piece.  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

RECTANGLE AREA = length x width

TRIANGLE AREA = 1/2 x width x height

CIRCLE AREA = 0.785 x diameter x diameter