Grout Calculator

This grout calculator can be used to predict the amount of grout that will be needed on a given tiling project.

The amount of grout that is required for a tiling project varies according to the size of the area to be tiled, the space between the tiles, and the depth the grout will need to fill. If you can measure these parameters, you can subsequently use this calculator to determine the amount of grout that will be needed in cubic feet, cubic inches, or gallons of grout.

First, ascertain the ratio of the area that will be covered with tiles (not grout). If the tiles that will be used have a width of W inches and a length of L inches, with grouting space of s inches, the proportion to be tiled will be as follows:

WL / [(W+s)(L+s)]

Second, determine the proportion of space that will be covered with grout by using the following equation:

1 − WL / [(W+s)(L+s)]

Multiply this figure by the grout depth in inches, denoted by d. Finally, multiply this figure by the total area of the space in square inches, A. If you have calculated the size of the area in square feet, multiply this figure by 144 to determine the square-inch equivalent (if you're using our grout calculator, you do not need to perform this conversion as our calculator will do it for you).

The formula used to determine the cubic inches of grout required to tile a given space is as follows:

Ad (1 − WL / [(W+s)(L+s)])

If you wish to convert the resulting figure to cubic feet, divide the estimation by 1728. If you want to convert it into gallons, divide it by 231.


Let's say Sarah wants to tile a floor space of 100 square feet using tiles that measure 5 inches by 5 inches. She intends to lay the tiles 0.25 inches apart on all sides, and the grout depth will be 0.25 inches.

The values used in the calculator will be as follows:

Area (A) = 100(144) = 14400 square inches,

Width (W) = 5 inches,

Length (L) = 5 inches,

Grouting space (s) = 0.25 inches,

Grouting depth (d) = 0.25 inches.

Inputting these values into the formula results in the following:

(14400)(0.25)(1 − (5)(5) / [(5.25)(5.25)])

= (3600)(1 − 25 / 27.5625)

= (3600)(0.09297)

= 334.692 cubic inches

= 0.1936 cubic feet

= 1.448 gallons

This calculator gives you a rough estimation of the amount of grout you would need to complete a tiling project. Always purchase a slightly higher amount of grout as a contingency.

Grout Volume Calculator

sq. ft.





You will need:

You may also be interested in our Tile Calculator

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