Flooring and tile calculator

Divide 1 m² by the area of one tile plus its joint. A 600 × 300 mm tile with a 3 mm joint covers 0.603 × 0.303 = 0.1827 m², so 1 m² takes 5.47 tiles; 300 × 300 mm tiles take 10.89. Multiply by the whole area before rounding up: rounding 5.47 up to 6 per m² would overbuy by about 10%.

About 98 twelve-inch tiles before waste. A 12 × 12 in tile with a ⅛ in joint covers 12.125 × 12.125 in, or 1.021 ft², so 100 ft² takes 97.95 tiles. Adding 10% for cuts and breakage gives 107.7, rounded up to 108 tiles.

This calculator's presets add 10% for a straight lay, 15% for a diagonal lay and 20% for herringbone, because angled layouts cut more tiles along every wall. On the default 12 m² floor those give 73, 76 and 79 tiles of 600 × 300 mm.

Multiply (A + B) ÷ (A × B) by tile thickness and joint width, all in mm, to get litres of joint per m². For 600 × 300 mm tiles 9 mm thick with 3 mm joints that is 900 ÷ 180,000 × 9 × 3 = 0.135 L per m², or 1.62 L for 12 m². The calculator converts at 1.6 kg per litre; check the grout bag's own coverage table.

Yes, they lower it slightly, because each tile plus its joint covers more floor. A 600 × 300 mm tile covers 0.18 m² on its own and 0.1827 m² with a 3 mm joint, so 12 m² needs 65.7 tiles instead of 66.7 before waste. For 50 × 50 mm mosaic with 3 mm joints, each tile's footprint grows by 12.4%.

정확도는 입력값과 계산 방법의 가정에 따라 달라집니다. 십진 연산은 유효숫자 50자리를 사용하지만, 추정값·수치해석 방법·원본 데이터의 정밀도는 더 낮을 수 있습니다. 표시값을 반올림해도 이러한 한계는 사라지지 않습니다. 독립적인 출처의 풀이와 대조한 계산 예시: 3. 예를 들어 “4 × 3 m floor, 600 × 300 mm tiles, 3 mm joints, 10% waste”은 Python decimal: 12 ÷ (0.603 × 0.303) = 65.68 × 1.1 = 72.25 → 73; grout (900/180000) × 9 × 3 × 12 = 1.62 L × 1.6 kg/L (Mapei formula); 10 boxes × 40 = 400와 대조해 확인합니다.

Mapei grout calculator — consumption (A + B)/(A × B) × C × D × 1.6 = kg/m²; TCNA Handbook for Ceramic, Glass, and Stone Tile Installation — joint widths and layouts.