Mosaic Tile Calculator — Sheets, Adhesive & Grout

Standard 300×300mm mosaic sheets cover 0.09 m² each, so you need approximately 11.1 sheets per m². With 10% wastage, order 13 sheets per m². Mosaic sheets come on mesh, paper, or dot-mounted backing. Mesh-backed sheets are the easiest to install as they flex around curves and the mesh stays behind the tiles.

Use a white flexible adhesive (C2 TE) for mosaic tiles — white is important for glass mosaics as grey adhesive shows through. Apply with a 3-4mm notched trowel for a thin, even bed. With a 3mm notched trowel, allow roughly 2.5–3 kg/m²; this calculator uses 3 kg/m² to keep a margin for absorbent backgrounds and back-buttering. Rapid-set adhesive is recommended to prevent sheets sliding. For glass mosaics, use a specialist glass tile adhesive like BAL White Star Plus.

Far more than large tiles. Grout demand depends on the individual chip size, not the sheet: smaller chips mean more joints per m². The industry formula is grout (kg/m²) = [(chip length + chip width) ÷ (chip length × chip width)] × joint width × joint depth × 1.8, where 1.8 kg/L is the density of cementitious grout. For 20mm chips at a 2mm joint and 4mm chip depth that is about 1.44 kg/m² — roughly three times a standard wall tile. Order accordingly.

Use unsanded (fine) grout for mosaic joints under 3mm. Epoxy grout is ideal for wet areas — it's waterproof, stain-resistant, and doesn't need sealing. Standard cementitious grout works well in dry areas. Apply with a rubber float, working diagonally across the sheets. Clean excess quickly — mosaic tiles have many joints and excess grout is harder to remove. Flexible mosaic/wall grout is most commonly sold in 2.5kg bags, so this calculator defaults to that bag size.

Cut between individual tiles using sharp scissors or a craft knife on the backing mesh. For cutting individual mosaic tiles, use tile nippers for simple cuts or a wet tile saw for precise cuts. Glass mosaics can shatter with nippers — score and snap or use a wet saw with a glass-cutting blade.

Yes — mosaic tiles are excellent for showers, especially on curved surfaces and shower floors where the small tile size follows the fall to the drain. Use waterproof adhesive and epoxy or waterproof grout. Ensure the substrate is fully tanked/waterproofed before tiling. The many grout joints actually improve grip, making mosaics ideal for shower floors.