How many tiles, grout bags, and thinset do I need?
Exact counts for floor, wall, and backsplash, with grout, thinset, backer board, and cost tiers built in.
Surfaces
Add a floor, wall, or backsplash. Each can use different tiles.
Quick-add a surface
Project details
Supplies checklist
Sized to this job: grout, thinset, trowel, float, spacers, and the saw rental.
- 1 bagGrout (25 lb bag)~$15
- 2 bagMedium-bed mortar (50 lb bag)~$50
- 1 eaNotched trowel (1/4″ × 3/8″ U-notch)~$15
- 6 sheetCement backer board (3' × 5')~$90
- 1 boxBacker board screws (200 pack)~$10
- 1 packTile spacers (1000 pack)~$8
- 1 eaRubber grout float~$12
- 2 eaLarge grout sponge~$8
- 50 clipTile leveling clips (if large-format)~$8
- 1 eaBucket (5 gal)~$6
- 1 dayWet tile saw rental (1 day)~$55
Ready to lay tile?
Kablan walks you through substrate prep, layout, thinset, grout, and cleanup, with tips matched to your specific tile and pattern.
FAQ
How is the tile count calculated?
We divide your surface area by the area of one tile to get a raw count, then multiply by a waste factor (10–20% depending on your chosen pattern). Diagonal, herringbone, and basketweave patterns require more cuts and produce more waste. We apply the factor automatically.
How many bags of grout do I actually need?
Grout coverage depends on tile size, grout joint width, and tile thickness. Small tiles with wide joints burn through grout fast; large-format tiles with thin joints use almost none. Our math approximates Custom Building Products and Mapei coverage tables: a 25-lb bag covers roughly 45 sq ft for 4×4 tiles at 1/8″ joints, 135 sq ft for 12×12 tiles at 1/8″, and less than 30 sq ft for mosaics with thick joints.
Do I really need backer board?
On floors: yes, almost always. Cement backer board (Hardiebacker, Durock) prevents flex that cracks tile and grout. On walls: only in wet areas like showers and backsplashes over sinks. Dry kitchen backsplashes are fine over drywall.
What pattern waste should I use?
Straight/stack layouts are the most efficient at ~10% waste. Diagonal adds ~15%. Herringbone, basketweave, and chevron all push 18–20% because every tile gets cut twice. First-time installers should add another 5% on top of these to cover measurement mistakes.
Ceramic vs porcelain vs natural stone, what's right for my project?
Ceramic is fine for walls and low-traffic floors; it's easier to cut and cheaper. Porcelain is denser, harder, and nearly waterproof: the right choice for bathroom and kitchen floors, wet areas, and high-traffic zones. Natural stone (marble, travertine, slate) is stunning but porous. It must be sealed and needs gentler cleaners. Choose by location and wear, not just looks.
Should I seal the grout?
Sanded grout on floors and in showers should be sealed. Sealing is cheap (~$20) and prevents staining from water, oil, and soap scum. Unsealed grout looks fine for six months, then discolors. Skip sealer only on pre-sealed urethane or epoxy grouts.
Can I rent a wet tile saw instead of buying one?
Yes. Home Depot and Lowe's rent wet saws for about $55/day. For one project, renting is the right call. If you're tiling multiple rooms or know you'll do more tile in the future, a basic tile saw runs $80–150 new.
Why don't my numbers match another calculator?
Most calculators ignore pattern waste, treat grout as a flat rate, and don't factor in thinset or backer board at all. Ours itemizes everything you'll actually put in the cart, using published coverage tables from major manufacturers.