Tile Calculator
Tile projects live or die on the takeoff: too few tiles and you are hunting a matching dye lot, too many and money sits in the garage. This tile calculator turns your floor or wall area and tile size into an exact tile count with a layout-matched waste allowance — 10% for straight, 15% for diagonal, 20% for herringbone. It also estimates thinset mortar bags and grout, so one trip covers the whole job.
Length of the floor or wall area to tile
Width of the floor or wall area to tile
Nominal tile size in inches
Nominal tile size in inches
Tiles needed
88
- Thinset mortar (50-lb bags)Rule of thumb: one 50-lb bag ≈ 90 ft²
- 1
- GroutRule of thumb: ≈ 1 lb per 10 ft² for 12-in tile
- 8lb
- Area incl. waste
- 88ft²
How it was calculated
- Project area = 10 ft × 8 ft = 80.0 ft²
- One tile = 1.000 ft × 1.000 ft = 1.000 ft²
- Tiles = ceil(80.0 × 1.10 ÷ 1.000) = 88
- Thinset = ceil(80.0 ÷ 90) = 1 bag(s); grout = 80.0 ÷ 10 = 8.0 lb
How it works
Each tile’s area in square feet is its length times its width, converted from inches: (L ÷ 12) × (W ÷ 12). A 12 × 12 in tile covers exactly 1 ft²; a 6 × 24 in plank covers 1 ft² as well.
The raw tile count is the project area divided by one tile’s area. Then the layout waste multiplier is applied — straight layouts waste about 10% on end cuts, diagonal about 15% because every perimeter tile is cut at an angle, and herringbone about 20% since the zigzag pattern generates the most offcuts. The result is always rounded up: tiles = ceil(area ÷ tile area × (1 + waste)).
Thinset mortar: a 50-lb bag covers roughly 90 ft² with a standard 1/4-in notched trowel (a rule of thumb — large-format tile and uneven substrates use more). Bags = ceil(area ÷ 90).
Grout: for common 12-in tile with standard joints, allow about 1 lb of grout per 10 ft² — a rule of thumb. Small mosaics with many joints need noticeably more; large tiles with tight joints need less.
Worked examples
80 ft² bathroom floor, 12 × 12 in tile, straight lay
Area is 10 ft × 8 ft = 80 ft². Each 12 × 12 in tile covers 1 ft², so the raw count is 80 tiles. Straight lay adds 10%: 80 × 1.10 = 88 tiles. Thinset: 80 ÷ 90 = 0.89 → 1 bag. Grout: 80 ÷ 10 = 8 lb.
120 ft² kitchen, 6 × 24 in plank tile, diagonal
Area is 12 ft × 10 ft = 120 ft². Each 6 × 24 in tile covers (6÷12) × (24÷12) = 0.5 × 2 = 1 ft², so the raw count is 120. Diagonal adds 15%: 120 × 1.15 = 138 tiles. Thinset: 120 ÷ 90 = 1.33 → 2 bags. Grout: 120 ÷ 10 = 12 lb.
How to measure
- Measure the tiling area in feet, wall to wall — tile is ordered for the full area, and fixtures get cut around.
- Measure tile in inches straight from the box, including the nominal size (a "12-in" tile is usually the nominal, not exact, dimension — close enough for estimating).
- For backsplashes and shower walls, measure height × length of each tiled section and add them.
- Count niches, half-walls, and curbs as separate rectangles and add them to the total.
- Note your grout joint width before buying grout — 1/8-in joints on small tile can double grout use versus the rule of thumb.
Assumptions & limitations
Planning estimate
- Thinset coverage (50-lb bag ≈ 90 ft²) and grout (≈ 1 lb per 10 ft² for 12-in tile) are rules of thumb for standard trowel sizes and joints — large-format tile, mosaics, and wide joints change consumption.
- Waste rates assume a reasonably rectangular area; showers with niches, benches, and multiple corners need extra.
- Tile dye lots vary — buy all tile at once from the same lot.
- This is a material estimate, not installation guidance; waterproofing and substrate prep are separate decisions.
Frequently asked questions
It depends on the layout: about 10% for a straight grid, 15% for diagonal, and 20% for herringbone. The extra covers perimeter cuts, broken tiles, and future repairs — tile dye lots change, so a cracked tile replaced two years later may never match. For complex shower floors with niches and benches, add a few percent beyond the layout rate.
A 50-lb bag of thinset covers roughly 90 ft² when spread with a standard notched trowel — divide your tile area by 90 and round up. Large-format tiles need a bigger trowel notch and back-buttering, which can cut coverage significantly, so buy an extra bag for those. Wall tile over a flat substrate lands close to the rule of thumb; uneven floors need more.
For standard 12-in tile with normal joints, budget about 1 lb of grout per 10 ft² of tile. Mosaics and small tiles have far more joint per square foot and can need two to three times that amount, while large tiles with tight 1/16-in joints need less. When in doubt, buy the next size up — grout is cheap compared to a second trip.
For floors, yes — tile the full rectangle and set fixtures on top of the tile wherever possible. It simplifies the layout, avoids awkward cuts, and leaves the floor finished if you remodel later. Only subtract areas that will never be tiled and are fully enclosed, like a walled-in tub deck.
The Flooring Calculator estimates plank and sheet goods — hardwood, laminate, vinyl, carpet — by the box. This page is tile-specific: it counts individual tiles from your tile dimensions, applies layout-based waste for straight, diagonal, and herringbone patterns, and adds thinset and grout. Use this page for ceramic, porcelain, stone, and mosaic tile.