Trowel size drives this number more than area does. Pick your notch to see bags.
How it works
Area ÷ coverage per bag for the notch, with 30% extra if you back-butter tile. Coverage uses the conservative end of published charts.
Before you order
- Comb ridges in one direction and press tile across them to collapse the ridges.
- Pull up a tile now and then to check that mortar is reaching the back.
- Large format tile often needs a mortar made for it and a bigger notch.
Common questions
What trowel size should I use?
Small wall tile can use 1/4 in notches, 12 in floor tile commonly uses 1/4 × 3/8 in, and larger tile needs bigger notches. Follow your mortar and tile maker.
Why does back-buttering add so much?
You are skimming a second layer on every tile. It adds around 30% on large tile.