Grout Calculator

Calculate the exact amount of grout needed for your tiling project based on area dimensions, tile size, and gap specifications.

Length of the area to be tiled

Width of the area to be tiled

Length of individual tile

Width of individual tile

Width of gap between tiles (in 1/16 inch increments)

Depth of gap to be filled with grout

Grout Material Details

Typical: 100 lb/ft³

Typical: 50% (1:1 ratio)

Standard bag weight

Results

Enter values and click Calculate to see results

Methodology

This calculator uses the professional tiling formula: R = (tile_length × tile_width) / ((tile_length + gap_width) × (tile_width + gap_width)), then calculates grout_area = total_area - (total_area × R), and finally grout_volume = grout_area × gap_depth. The calculation accounts for gaps between tiles and around the perimeter. Material requirements are calculated based on grout density and typical mixing ratios.

About This Calculator

1. How does the Grout Calculator work?

This calculator uses the formula from professional tiling: First, it calculates the ratio R = (tile length × tile width) / ((tile length + gap) × (tile width + gap)). Then it finds the grout area = Total area - (Total area × R). Finally, it multiplies the grout area by the gap depth to get the volume needed. The calculation accounts for gaps around the perimeter and between all tiles.

2. What type of grout should I use?

The grout type depends on your gap width: Use unsanded grout for gaps ≤ 1/8" (fine particles, smooth finish), sanded grout for gaps 1/8" to 1/2" (contains sand for strength and prevents shrinkage), and wide joint grout or mortar for gaps > 1/2". For high-moisture areas like showers, consider epoxy grout for superior water resistance.

3. How much extra grout should I buy?

Always buy 10-15% extra grout beyond the calculated amount. This accounts for waste during application, mixing errors, and future repairs. It's also important to buy all grout from the same lot/batch to ensure consistent color, as different production runs may have slight color variations.

4. What is the mixing ratio for grout?

Most dry grout mixes use approximately a 1:1 ratio of water to powder by weight (50% dry material). However, always follow the manufacturer's specific instructions on the package, as different grout types and brands may have different requirements. Mix only what you can use in 30 minutes, as grout begins to set quickly.

5. How deep should grout be applied?

Grout depth should typically be at least 2/3 the thickness of your tile. For most ceramic tiles (1/4" to 3/8" thick), a grout depth of 1/4" to 3/8" is appropriate. Thicker tiles may require deeper grout lines. The gap depth in this calculator refers to how deep you'll fill the space between tiles with grout.

6. Are there limitations to this calculator?

This calculator provides estimates based on standard tiling practices and assumes uniform tile spacing. Actual grout needs may vary due to tile irregularities, installation variations, waste during application, and mixing. For complex patterns, irregular tiles, or mosaic work, consider adding extra material. Always consult with tile professionals for large or complex projects.