This Grout Calculator, or more particularly, tile grout calculator, is for you if you’re asking, “How much grout do I need for my tiling project?” Using this calculator, you’ll discover what tile grout or tile gap filler is and how to calculate cement grout volume for any floor or wall area, tile size, and tile gap.

What is tile grout?

Tile grout is a substance used to fill in the spaces between the tiles to keep dirt and fluids out. When laying tiles, we leave spaces between them to reduce the likelihood of future breaking or to lift off tiles due to floor or wall thermal or structural deformation, tile expansion, or tile movement. In addition, tile grout enhances the aesthetics of a tile installation, particularly when using ceramic tiles.

Grout, like concrete and mortar, is a composite material that is normally a combination of cement, lime, and water and can also contain sand. Epoxy and polymerbased grouts are ideal for regions that require a high level of resistance to moisture and chemicals. With that in mind, we can purchase dry pre-mixed cementitious grout in bags or 2-part epoxy hardener and resin bottles.

How do you calculate cement grout volume?

You can determine the volume if you know the cement’s specific gravity. The weight of the cement is divided by the weight of an equivalent volume of water to get the specific gravity. For example, 1 cubic foot loose volume of portland cement weighs 94 pounds and has a specific gravity of 3.15. The amount of cement is 0.478 cubic feet when the weight, 94 pounds, is divided by the specific gravity times the unit weight of water (62.4 pounds per cubic foot). The weight of a gallon of water is 8.33 pounds. Therefore, 0.667 cubic feet of water is obtained by multiplying the weight of 5 gallons of water (8.33 x 5) by 62.4 pounds per cubic foot (PCF).

To figure out how much grout we’ll need, we’ll need to know the entire volume of the space between our tiles. So we used the R ratio of the area of a single tile to the area of a single tile with half of the gap surrounding it in this calculator, as shown below:

R = l x w / ((l + g) x (w + g))

  • L is the length of the tiles to be installed,
  • w is the width of the tiles to be installed, and
  • G is the gap width or tile spacing that needs grouting.

We can then use the calculation below to calculate the total area covered by the tile grout using this ratio:

grout area = A surface – A surface x R

How do you use our grout calculator?

Enter the measurements of the area that requires tiling, the size of your tiles, and the required gap width and depth into our grout calculator. Our grout calculator will show you how much grout you’ll need for your job right away. We’ve also provided a rough estimate of how many bags of dry pre-mixed grout you’ll need for your job.

How many bags of grout do I need per square foot?

 FLOOR APPLICATIONWALL APPLICATION TROWEL SIZE
(based on largest dimension)
COVERAGE
(based on 50lbs bag)
 Mesh Mosaics Mesh Mosaics 3/16 inch V-Notch 90 – 100 Sq Ft
 4 inch – 12 inch Tile  4 inch – 12 inch Tile 1/4 inch Square 75 – 85 Sq Ft
 12 inch – 16 inch Tile  12 inch – 16 inch Tile 3/8 inch Square 60 – 70 Sq Ft
 16 inch or larger 16 inch or larger 1/2 inch Square or V-Notch 40 – 50 Sq Ft
 Tile thicker than 3/8 inch Tile thicker than 3/8 inch 1/2 inch Square or V-Notch 40 –  50 Sq Ft
 Ungauged Tile ** Ungauged Tile ** 1/2 inch Square or V-Notch 40 – 50 Sq Ft
 Cement Board Installation  1/4 inch Square 75 – 85 Sq Ft
Table of ways of application with a number of bags needed

FAQ

How do you figure out how much grout you need?


Here are four steps how you can calculate it:
1: A is equal to tile width (mm) + tile height (mm).
2: B = tile thickness (mm) x spacer size (mm).
3: C = A x B x 1.2 (the coverage ratio of all UltraTile grouts).
4: D = tile width (mm) multiplied by tile height (mm).

How many m2 will a 10kg bag of grout cover?

+/- 0.5m2 per 1 kilogram bucket for floors Per 1 kilogram bucket, walls: +/- 0.6m2. Floors: a 300 × 300 tile with a 5mm joint will cover +- 11m2 every 5kg bag. For walls, a 200 × 250 tile with 3mm joints will cover +- 15m2 every 5kg bag.

How much will 5 kg of grout cover?

Approximate coverage: 23-24m2 with 2mm grout joints on 300x300x10mm tiles.