how do you find the square footage when using 18x18 tiles?

Ah, one thing is missing in all answers. You have to allow for space that grout will use up. It is number of square ft. as you'd normally measure, but add 10% extra for waste, errors & grout. If you have a 10x6' room, that's 60 sq. ft. Multiply length x width. If you're tiling under cabinets, etc. that's perfect. If not, don't worry about subtracting for these things; that can be your waste/error factor.

~m~

Take the width of the room and divide by 1.5 (18" is 1.5 feet). That will give you the number of tiles in that direction. Round UP to the next whole number.

Take the length of the room and divide it by 1.5 (18" is 1.5 feet). That will give you the number of tiles in that direction. Round UP to the next whole number.

Multiply the number of tiles in the width by the number of tiles in the length. That will give you the number of tiles you'll need.

If your room is:

10ft x 12ft, take the 10 and divide by 1.5. You get 6.667. Round up to 7 whole tiles.

Take the 12ft and divide by 1.5. You get 8. Don't need to round up on this one.

Multiply 7 x 8 and you get 56 tiles for the room presuming you don't have many mistakes when cutting or you don't have any weird corners or angles to cut around. Add more tiles (usually 10% more).

There's more math involved when you lay out the tiles so you don't end up with a narrow sliver of a tile (like 1" wide) along the wall. Here's how you do that:

1. Take the width of the room in inches (10ft x 12" = 120").

2. Divide by the width of the tile (18"). The 18"includes the room for grout. 120"/18" = 6.667. Drop the whole number 6.

3. Take the remainder .667 and multiply by 18" then divide by 2. (.667 x 18)/2 = 6". Six inches is the width of the tiles along each edge of the room along that width.

4. Take the exact center of the room and move the center line 6" in either direction. That becomes your new center line for laying the tiles across the width of the room. Each 18" tile will net you two 6" border tiles, maybe a third border tile depending upon the tile design.

Do the same for the length of the room.

You see, there's more math to laying tiles than just laying tiles. If not done correctly, it will look like an amateur did the work.

I no numbers and math it these tile of differ sizes 10 tiles 18X18 , 6 tiles 11.5 X 23.5 and 10 cases tiles of 12X12 10 in box bath tub area is 6 ft up side is 27 inch by 54 inch

You count the number of 18 X 18 tiles on the floor. You multiply that number by 9. Then you divide that result by 4. That gives you the square feet of your floor

It works just the opposite when you want to know how many 18 X 18 tiles are needed. You measure the square feet of the floor. You multiply the square feet by 4 and you divide that result by 9.

See how easy that was?

Measure the area that you are tiling and then divide it by the area of one tile. This will give you the number of tiles you will need.......... not allowing for grouting, which will mean that you will need a few tiles less than this figure.

So if your room is ten feet long and five feet wide the area is fifty square feet... right ? 10 x 5 = 50 sq feet. Your tile is 1.5 ftx1.5ft = 2.25 sq feet. Therefore 50 divided by 2.25 gives you 22/23 tiles.

Divide your room in two and lay your tiles on either side of this line so as not to have small slivers of tile at the edges. Use a spirit level to keep them level and use tile spacers to keep them the same distance apart.

an 18 by 18 tile has 324 square inches. Measure your room length and width (in inches) Multiply the two and divide by 324.

Example: A 12' X 12' Room

144 inches times 144 inches = 20736 square inches

20736 Divided by 324 = 64

you will need 64 tiles to do the room.

Each of your tiles is 1 1/2 x 1 1/2 = 2 1/4 square feet ( 'cos if the tile was 12" x 18" that would be 1ft x 1 1/2 ft = 1 1/2sq.ft tricky eh!)

So area of floor divided by 2 1/4 = number of tiles

Example

Floor measures 8ft by 12ft = 96 sq. ft.

so 96 divided by 2 1/4 = 42 2/3 tiles

Then add some for waste cuts

If you don't believe it. 6 tiles is just too long for the 8ft and 8 tiles is exactly 12ft so

6 rows of 8 tiles is 48 with 8 half tiles waste

The laying pattern will alter the number needed in practice

ie what shape is the floor? do you want diagonal lay

Good Luck

It is very simple.

One 18"x18" tile is 2.25 square feet. the calculation is like this:

18 x18=324 that is 324 square inches.

take that and divide it by the suare inches in a square foot (144) and you get 2.25, 2.25 squre feet per tile.

You can apply the same formula for any size room:

Length times width divide by the unit desired, square feet, square inches etc.

For example , a room 10 by 10 feet is

10x10=100 , 100 square feet,

100 square feet times 144 equals 14400 square inches etc.

so a room 20' x20' would be 400 square feet so you would need 178 tiles plus 10% waste.

Hope this helps,

Check out my website, tricks-of-the-trades.com for tricks on the install.

Tell us the dimensions of the room and let us do it for you.

Or, measure the width and length of the area to be tiled. Round the measurement up to the nearest 1/2 ft if it does not fall evenly on either a full foot or half foot. For instance a 10'1" measurement would round up to 10.5 feet and a 10'8" measurement would round up to 11'. Notice I used a decimal for the half foot measurement. The decimal is to make it easier to calculate later.

Each tile is 1.5 feet. So divide each of the two measurements by 1.5 and round up to the nearest whole number.

Multiply the two whole numbers to find the total number of tiles required. Now to get the price per square foot you will have to multiply the total number of tile by 2.25 square feet per tile.

An example using the 10'1" x 10'8" room. 10'1" rounds to 10.5. 10'8" rounds to 11. divide 10.5 by 1.5 to get 7. 11 divided by 1.5 is 7.33 which rounds up to to 8. Multiply the 7 and 8 to get 56 total tiles. The total square feet of tile is 126. This is the maximum number of tile you would need.

18 x 18 = 18 sq in. which = 1.5 sq ft. 170 / 1.5 = 113.3 Buy about 130 of them, you'll have to cut some of them to get them to fit. Wouldn't hurt to buy 150 just in case.