To estimate the amount of tile you will need for a mosaic project first determine the area of the object you wish to mosaic, then measure length and width.
Next, calculate the square feet of the area by using the following equation: Length x Width = Sq Ft
Add 10% of the total square feet to account for waste:  Sq ft x .10 =  Waste
Then add the total square feet to the total waste :  Sq ft + Waste = Amount of Tile Needed

Therefore,  Length x Width + Waste = Amount Needed

For instance, if your room is 12 ft by 14 ft, the square footage would be 168 square feet.  You must then add 10% to that number for waste.

Example:
12ft x 14ft = 168 Sq ft
168 x .10 = + 16.8 Sq ft (for waste)
168 + 16.8 = 184.8 Total Sq ft of tile needed

*If purchasing mosaic stained glass from Katie Hall Mosaics, then our 13oz bags of different size glass pieces will roughly cover a 6 inch square surface with 1/8 inch- 1/4 inch grout joints.

The following table is a basic idea of the about of mosaic tile needed per sq ft (with 1/8" grout joint).

Tile Size	Tiles per sq Ft
Tiny Tiles (3/8")	1.4 lbs
Vitreous Glass Tiny Tiles	1 lbs
¾” Vitreous Glass Tiny Tiles	225 tiles
Smalti (no space for grout)	2 1/2 lbs
4" X 4"	9
4 ¼" X 4 ¼"	8
6"X 6"	4
8" X 8"	2.25
10" x 10"	1.45
12" x 12"	1