How much tile adhesive do I need?
Adhesive quantity depends on three things: the area, the trowel size and the tile size. A 50 lb bag of thin-set covers roughly 90-100 square feet with a 1/4 inch notched trowel — much less for large-format tiles, which need a 3/8 or 1/2 inch trowel. Check the bag's coverage table before ordering.
Always add waste: adhesive is lost to the trowel, the bucket and evaporation. On older or uneven substrates you may need a thicker layer to level the floor, which increases usage significantly. For large-format or stone tiles, doubled coverage calculations are common in practice.
Quick reference
- 1/4" notched trowel: ~90 sq ft per 50 lb bag
- 3/8" notched trowel: ~60-70 sq ft per bag
- 1/2" notched trowel: ~40-50 sq ft per bag