About this calculator
Bags of thinset mortar by area and trowel size.
How it’s calculated
Coverage per 50 lb bag: about 90 sq ft with a ¼" square notch, 70 sq ft with ¼" × ⅜", and 45 sq ft with ½" square.
Worked example
With these inputs:
- Measure by
- Length × width
- Length
- 15 ft
- Width
- 12 ft
- Trowel notch
- ¼" × ¼" square
- Back-butter tiles (+30%)
- No
- Waste allowance
- 10%
the result is:
- Thinset bags (50 lb)
- 3 bags
Tips from the trade
- Choose the notch for the tile size: bigger tiles need bigger notches.
- Lift a tile now and then to check for full coverage.
Results are estimates for planning and pricing. Check quantities against your drawings, the manufacturer’s data and the building code adopted in your province before ordering.