Mortar/Thinset Calculator
Calculate how many bags of thinset mortar you need for your tile installation based on area and trowel size.
Results
Visualization
How It Works
Thinset mortar bonds tile to the substrate. Coverage depends on trowel notch size — larger notches lay more mortar for bigger tiles.
The Formula
Bags = Area / Coverage per Bag (by trowel size)
Variables
- Area — Total square footage to tile
- Coverage — Sq ft per bag, varies by trowel notch size (40-95 sq ft)
Example
120 sq ft with a 1/4"x1/4" trowel: 120 / 80 = 1.5, round up to 2 bags of 50-lb thinset.
Tips
- Use modified thinset for porcelain and large-format tiles.
- Back-butter large tiles (>15") in addition to troweling the substrate.
- Mix thinset to peanut butter consistency — it should hold trowel ridges.
- Only spread as much thinset as you can tile in 15-20 minutes.