How many tiles do I need?

Divide the floor area by the area each tile plus its grout joint covers, then add waste by pattern. A 144 square foot floor in 12 by 24 inch tile laid straight is about 78 tiles with 10 percent waste. The calculator does the grout-joint math and the pattern waste; buy a box or two extra for future repairs, since dye lots change.

How much thinset and grout do I need for tile?

Thinset depends on trowel size: a 50 pound bag covers about 95 square feet at a 1/4 inch notch for small tile, dropping to about 30 square feet at a 3/4 inch notch for large-format. A 144 square foot floor in 12 by 24 tile takes about 4 bags of thinset and one 25 pound bag of grout. Wet areas and stone need more thinset because they require 95 percent back coverage.

How much waste should I add for tile?

By pattern: 10 percent for a straight lay, 12 for running bond, 15 for a diagonal, and 20 for herringbone, because angled and offset cuts waste more tile at the walls. Mosaic sheets run about 5 percent. The calculator pre-loads the waste from the pattern you pick and lets you raise it for an out-of-square room.

Can you lay large-format tile in a running bond?

Only up to a 33 percent offset. ANSI A108.02 caps the running-bond offset on tile with any side over 15 inches at one-third of the tile length, because the natural bow in a big tile lifts the corners into lippage past that. Offset a 24 inch tile no more than 8 inches, use a leveling-clip system, or lay it straight. The calculator warns when a large tile is set in an offset pattern.

MATERIALFOREMAN · SHEET T-001 · FINISH WORKS

CALC-001 · DRAWING NO. T-001 · REV A

Tile calculator.

Drafted to scale · cited sources · honest numbers

Enter the floor area and tile size. The calculator returns tile count, thinset bags, grout bags, and a material-cost range. Waste is pre-loaded by pattern (straight 10%, running bond 12%, diagonal 15%, herringbone 20%, mosaic 5%) and adjustable. Fires an ANSI A108.02 warning on large-format tile in running bond.

◈ DRAFTING PANEL · TILE TAKEOFF · N.T.S. SHEET T-001 · REV A

Redline · scope notice Floor tile only. Does not compute wall tile, shower surrounds, backsplashes, waterproofing membrane, or backer board. Handles rectangular areas; L-shapes and niches require separate takeoffs summed. Mortar coverage assumes 50 lb bags of modified thinset at manufacturer-published rates.

Note 01 · Field Procedure

How to measure the floor

Measure wall to wall in both directions. Record the longest run on each axis, not the shortest. Tile layout starts from center, so the longest dimension drives cut count at the perimeter.
Record length and width in feet. Round up to the nearest half foot for irregular walls or bump-outs.
Pick the grout width before ordering. Standard ceramic uses 1/8 in. rectified joints; non-rectified tile requires 3/16 in. minimum. Wider joints shift the effective tile size and change the count.
Choose the layout pattern before calculating. Running bond adds 12% (brick-lay offset). Diagonal adds 15% (45-degree cuts at every wall). Herringbone adds 20% (angled interlocking cuts). Mosaic is 5% (small tiles, fewer cuts). Straight lay is the most material-efficient at 10%.

Note 02 · Equation

The formula

tiles = ⌈ A × 144 ÷ ( tL + g ) × ( tW + g ) × ( 1 + w ÷ 100 ) ⌉

Afloor area in square feet

tL, tWtile length and width in inches

ggrout joint width in inches

wwaste percentage (pattern-dependent)

144square inches per square foot

⌈ ⌉ceiling function (round up to whole tile)

Note 03 · Sanity Ranges

Tiles by project size

T	Use case	Notes
40 sf	Entry / foyer	24×24 straight: ~44 tiles. Small room, large tile.
60 sf	Laundry room	12×12 straight: ~66 tiles. Standard utility layout.
80 sf	Bathroom floor	12×12 straight: ~87 tiles. Most common DIY tile job.
150 sf	Kitchen floor	12×24 straight: ~82 tiles. Large format cuts tile count.
200+ sf	Open-plan living	24×24 diagonal: adds 15% waste. Budget for extra boxes.

Note 04 · References

Sources

Authorities cited on this sheet

TCNA Handbook 2026: Ceramic, Glass, and Stone Tile Installation · Tile Council of North America. Defines installation methods, mortar coverage requirements, grout joint minimums, and waste factors by pattern. The primary reference for tile takeoff methodology.
ANSI A108 Tile Installation Standards (administered by TCNA) · ANSI A108.02 Section 4.3.8.1: large-format tiles (any side over 15 in.) shall not exceed 33% running-bond offset. Enforced as a hard warning in this calculator.
Custom Building Products VersaBond Thinset Mortar · 50 lb modified thinset. Coverage by trowel size: 1/4×1/4 in. ~95 sf, 1/2×1/2 in. ~50 sf, 3/4×3/4 in. ~30 sf. Basis for the thinset bag count on the spec slip.
Custom Building Products Polyblend Plus Sanded Grout · 25 lb bag yields ~0.14 ft3 (~242 in3). Grout bag count is computed from joint-volume geometry, not a flat lookup, because consumption varies dramatically with tile size.

Note 05 · Field Manual

What the sheet count does not tell you

A 12 by 12 kitchen floor, worked out

Take a 12 by 12 foot floor, 144 square feet, in 12 by 24 inch porcelain laid straight. Each tile plus its 1/8 inch grout joint covers about 2 square feet, so the field needs about 71 tiles; add the 10 percent straight-lay waste and the order is 78 tiles. Thinset follows the tile size: a 12 by 24 is large enough to need a 3/4 inch notched trowel, which spreads about 30 square feet per 50 pound bag, so 144 square feet at 80 percent coverage takes 4 bags. Grout is geometry, not a flat lookup: at a 1/8 inch joint the floor needs about one 25 pound bag. Materials run roughly 300 to 1,240 dollars depending on whether the tile is builder porcelain or a mid-range stone-look.

Thinset, trowel size, and back-butter

Thinset coverage is set by trowel size, and trowel size is set by the tile. Small tile up to 8 inches uses a 1/4 inch notch that spreads about 95 square feet per bag. Mid tile to 16 inches uses a 1/2 inch notch at about 50 square feet. Large-format tile over 16 inches needs a 3/4 inch notch and drops to about 30 square feet per bag, because the bigger ridges it takes to fully bed a big tile use more mortar. Two adjustments raise consumption further. Wet areas and any natural stone need 95 percent mortar coverage on the back of the tile, against 80 percent for a dry floor, which the calculator applies automatically. And large-format tile lives or dies on full coverage: a hollow spot under a big tile is a crack waiting for the first dropped pan.

Large-format lippage and the ANSI rule

Large-format tile, anything with a side over 15 inches, has a layout rule that trips up the popular brick-lay look. ANSI A108.02 caps the running-bond offset on large-format tile at 33 percent of the tile length. Offset a 24 inch tile more than 8 inches and the natural bow every large tile carries lifts one edge above its neighbor, which is lippage: the little ridges you stub a toe on and catch a mop on. The calculator fires a hard warning when you put a large-format tile in any offset pattern, because past the 33 percent line it needs installer verification and often a leveling-clip system. Straight lay sidesteps the whole problem. If you want the offset look on a big tile, confirm the bed and the offset with your installer before ordering.

Note 06 · Common Questions

Common questions

How many tiles do I need?: Divide the floor area by the area each tile plus its grout joint covers, then add waste by pattern. A 144 square foot floor in 12 by 24 inch tile laid straight is about 78 tiles with 10 percent waste. The calculator does the grout-joint math and the pattern waste; buy a box or two extra for future repairs, since dye lots change.
How much thinset and grout do I need for tile?: Thinset depends on trowel size: a 50 pound bag covers about 95 square feet at a 1/4 inch notch for small tile, dropping to about 30 square feet at a 3/4 inch notch for large-format. A 144 square foot floor in 12 by 24 tile takes about 4 bags of thinset and one 25 pound bag of grout. Wet areas and stone need more thinset because they require 95 percent back coverage.
How much waste should I add for tile?: By pattern: 10 percent for a straight lay, 12 for running bond, 15 for a diagonal, and 20 for herringbone, because angled and offset cuts waste more tile at the walls. Mosaic sheets run about 5 percent. The calculator pre-loads the waste from the pattern you pick and lets you raise it for an out-of-square room.
Can you lay large-format tile in a running bond?: Only up to a 33 percent offset. ANSI A108.02 caps the running-bond offset on tile with any side over 15 inches at one-third of the tile length, because the natural bow in a big tile lifts the corners into lippage past that. Offset a 24 inch tile no more than 8 inches, use a leveling-clip system, or lay it straight. The calculator warns when a large tile is set in an offset pattern.

PROJ MATERIALFOREMAN

SHT T-001 / 014

REV A · 2026-06-07

DRAWN MF