How Much Tile Grout Do I Need?

Why there is no single number

Small tiles have more joints per square foot than large tiles, and wide or deep joints take more grout. Mapei says its coverage chart is approximate and lists coverage by tile size, tile thickness and joint width. The figures here are for Mapei Keracolor S sanded grout, which fills joints from 1/8 to 5/8 inch. Other brands have their own charts, so use the chart for the product you buy.

Coverage per 25 lb bag (sq ft)

• 2 x 2 x 1/4 in tile: 93 at 1/8 in joints, 61 at 3/16, 45 at 1/4, 29 at 3/8.
• 4 x 8 x 1/2 in tile: 127, 84, 63 and 42.
• 6 x 6 x 1/4 in tile: 285, 190, 142 and 93.
• 8 x 8 x 3/8 in tile: 255, 169, 126 and 84.
• 12 x 12 x 3/8 in tile: 383, 253, 191 and 126.
• 16 x 16 x 3/8 in tile: 510, 340, 255 and 169.
• 24 x 24 x 3/8 in tile: 768, 510, 383 and 255.

Worked examples

Pounds of grout per 100 sq ft is 25 x 100 / coverage. For 12 x 12 x 3/8 tile at 1/8 inch joints: 25 x 100 / 383 = 6.5 lb. At 1/4 inch joints: 25 x 100 / 191 = 13.1 lb. Either way, 100 sq ft is one 25 lb bag.

For 4 x 8 x 1/2 tile at 1/8 inch: 100 / 127 = 0.79 of a bag, so one bag. For 2 x 2 mosaic at 1/8 inch: 100 / 93 = 1.08 bags, so two bags. Round up and keep any leftover for repairs, since later batches can differ slightly in color.

Tips

• Measure your tile thickness. The chart rows assume a thickness, and thicker tile uses more grout.
• Wider joints take far more grout: going from 1/8 to 1/4 inch roughly doubles the amount.
• Check the bag for the joint widths the product is made for. Sanded grout is for wider joints; unsanded products have different ranges.
• Waste: advice varies. One non-official site suggests 5 to 10 percent extra tile for straight layouts and 15 to 25 percent for diagonal, and we could not confirm a standards body figure, so treat it as a rule of thumb and ask your tile supplier.

Frequently asked questions

Sources: Mapei Keracolor S installation instructions and coverage chart. Read 7 November 2026.