Tile planning

How Much Thinset and Grout Do I Need for Tile?

A 50 lb bag of thinset covers roughly 80 to 100 square feet with a 1/4 inch square-notch trowel, 60 to 70 square feet with a 1/4 x 3/8 inch notch, and 40 to 50 square feet with a 1/2 inch notch. Grout varies too much for one number, so use the chart on the bag.

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Thinset coverage by trowel size

Bigger tiles need a deeper mortar bed to get full contact, so they use a larger trowel notch and more thinset per square foot. These are typical label ranges for a 50 lb bag.

Typical thinset coverage per 50 lb bag by trowel notch
Trowel notchTypical tile sizeCoverage per 50 lb bag
1/4 x 1/4 in squareUp to about 8 in80 to 100 sq ft
1/4 x 3/8 in squareAbout 8 to 16 in60 to 70 sq ft
1/2 x 1/2 in square16 in and larger40 to 50 sq ft

How many bags of thinset by area

Divide the area by the coverage range for your trowel and round up. The lower count assumes the high end of the label range, the higher count the low end. Buy the higher count for large tiles and uneven floors.

50 lb bags of thinset by area and trowel notch
Area1/4 x 1/4 in notch1/4 x 3/8 in notch1/2 x 1/2 in notch
30 sq ft1 bag1 bag1 bag
50 sq ft1 bag1 bag1 to 2 bags
100 sq ft1 to 2 bags2 bags2 to 3 bags
200 sq ft2 to 3 bags3 to 4 bags4 to 5 bags
500 sq ft5 to 7 bags8 to 9 bags10 to 13 bags
1,000 sq ft10 to 13 bags15 to 17 bags20 to 25 bags

A worked thinset example

A 60 square foot bathroom floor in 12 x 24 inch tile uses a 1/2 inch notch. At 40 to 50 square feet per bag, one bag will not finish the job, so buy two. Back-buttering large tiles, which most manufacturers recommend, uses a little more.

Estimating grout

Grout use depends on four things: tile length, tile width, tile thickness, and joint width. Small tiles with wide joints use many times more grout than large tiles with tight joints, so a single rule of thumb is unreliable.

The joint volume per square foot is (tile length + tile width) / (tile length x tile width) x 144 x joint width x tile thickness, in inches. The table converts that volume to pounds at roughly 0.06 lb per cubic inch of sanded grout and rounds it, so treat it as a starting point and confirm with the chart on your bag.

  • Use the coverage chart on the grout bag or the manufacturer calculator with your exact tile and joint size.
  • Mosaics and small subway tile can use several pounds of grout per 10 square feet.
  • Large-format floor tile with 1/8 inch joints often needs only one small bag for a whole bathroom.
  • Sanded grout is for joints 1/8 inch and wider. Unsanded is for narrower joints and easily scratched tile.
Approximate pounds of sanded grout per 100 sq ft
Tile size and thicknessJoint widthGrout per 100 sq ft
12 x 24 in, 3/8 in thick1/8 inAbout 5 lb
12 x 12 in, 3/8 in thick1/8 inAbout 7 lb
12 x 12 in, 3/8 in thick3/16 inAbout 10 lb
6 x 6 in, 5/16 in thick1/8 inAbout 11 lb
3 x 6 in subway, 5/16 in thick1/16 inAbout 8 lb
2 x 2 in mosaic, 1/4 in thick1/8 inAbout 27 lb

The rest of the starter list

Add spacers or a leveling system, edge trim for exposed tile edges, a mixing bucket and paddle, a margin trowel, a grout float, sponges, and sealer if the tile or grout calls for it.

Wet areas are a different project. A shower or tub surround needs a complete waterproofing system behind the tile, installed to the manufacturer instructions. Tile and grout alone are not waterproof.

Key takeaways
  • Thinset coverage falls as trowel notch size goes up.
  • Size grout from the bag chart using your tile and joint dimensions.
  • Showers need waterproofing behind the tile, not just tile and grout.

Run the numbers

The Tile Calculator applies this math to your own measurements and shows each step. Best for planning a bathroom floor, laundry room, backsplash, or entryway tile job.

Related guides

About this guideQuantities are planning estimates based on typical product labels. Verify coverage on the product you buy, and check local prices and code. See our methodology.