Tile Square Footage Calculator

Manual deductions do not change the displayed results. This tool has no opening-deduction or net-area input. Its allowance, boxes and cost all use the geometry you entered. If you subtract openings on paper, calculate the downstream allowance, boxes and cost manually too, unless the entered non-overlapping sections already exclude those openings.

How to Calculate Tile Square Footage

1. Measure the installed surface — floor, wall, or backsplash. For a rectangle, multiply length × width; add separate sections and manually deduct measured untiled openings.
2. Choose a purchasing allowance: net area × (1 + allowance percentage ÷ 100). Use this formula manually after any separate deductions; the widget's waste setting still acts on its entered geometry.
3. Use the actual coverage per box: boxes = ceil(allowance-adjusted net area ÷ coverage per box). Here, ceil means round up to the next whole number. The widget's coverage field gives this net-based result only when its entered geometry already matches the net surface.
4. Check a separate cut plan before ordering. The tool has no tile-size, grout-joint, individual-piece, or layout inputs. The manual examples below explain why an area estimate can differ from a physical tile count.

For a 10 × 8 ft wall excluding a 3 × 7 ft opening, net area is 80 − 21 = 59 sq ft. With an illustrative 10% allowance, 59 × 1.10 = 64.9 sq ft; at 10 sq ft/box, ceil(64.9 ÷ 10) = 7 boxes. At an assumed $4/sq ft, the net-area-based allowance estimate is $259.60, while seven whole boxes covering 70 sq ft would cost $280 at that material rate. Leaving the original 10 × 8 dimensions in the widget instead shows 9 boxes and $352 on 88 allowance-adjusted sq ft. Its cost is an area-price estimate, not a whole-box invoice.

Choosing an Allowance Without a Layout Promise

The 10% and 15% allowances used below are illustrative purchasing assumptions, not recommended rates for particular patterns. Actual needs depend on the field dimensions, tile dimensions, pattern, edge cuts, reusable offcuts, and breakage. Keep repair reserves identifiable so they are not counted twice. A percentage cannot replace a cut plan; see the centered edge-cut example.

Nominal Tile-Area Equivalents for Common Sizes

This table treats every listed dimension as exact. Tile face area in square feet = length in inches × width in inches ÷ 144. The last column is ceil(100 ÷ tile face area), with whole-number rounding only: no purchasing allowance, joint spacing, perimeter gaps, or layout calculation. These are nominal area equivalents, not a guarantee that the listed number of physical tiles will cover a particular room.

For 100 sq ft plus an example 10% allowance, the purchasing area is 110 sq ft: 110 nominal 12 × 12 equivalents, 55 nominal 12 × 24 equivalents, or ceil(110 ÷ 2.25) = 49 nominal 18 × 18 equivalents. A product's nominal size may differ from its actual dimensions. Joint spacing, saw kerf (material lost to the blade), cuts, and layout must be checked separately.

Example: 8 × 10 Bathroom Area Estimate

• Installed area: 8 × 10 = 80 sq ft.
• Illustrative allowance: 10% → 88 sq ft.
• Nominal equivalents at exact 12 × 12 inch dimensions: 88 ÷ 1 = 88.
• If labeled box coverage is 10 sq ft: ceil(88 ÷ 10) = 9 boxes, providing 90 sq ft of labeled coverage.

This is area-to-box arithmetic only. Verify the actual cut plan and supplier's selling units before treating it as an order quantity.

Walls, Backsplashes, and Trim

Measure the actual height and length of each tiled wall section rather than assuming a standard backsplash height. Add the areas, then manually deduct measured openings where no tile will be installed. Small outlet openings can still require a whole tile blank to cut around them, so their area deductions do not directly translate into fewer tiles to buy.

For example, a measured 10 ft × 4 ft tiled section is 40 sq ft; an illustrative 10% allowance gives 44 sq ft before box rounding. Measure exposed edges separately for trim: use edge length, available trim-piece lengths, and corner cuts rather than the field's square footage.

Grout, Mortar, and Sealer Are Separate Estimates

Tile purchasing allowance includes material that may become offcuts, breakage, or stored spares. Do not use that extra area as the installed area for grout or mortar.

• Grout: use installed area, actual tile dimensions, joint width and depth, tile profile, and the selected manufacturer's coverage data. There is no universal pounds-per-square-foot rate.
• Mortar or other setting material: use installed area and the selected system's product instructions for the actual substrate, tile profile, trowel, and application method. This calculator does not determine compatibility or bag coverage.
• Sealer: first check whether the selected tile and grout require it. If specified, use the product's coverage, coat count, and maintenance instructions for the surface being treated.

Pattern Choices Need Their Own Cut Plan

Straight, running-bond, diagonal, herringbone, and basketweave patterns place edges and joints differently. Draw the selected pattern using actual product dimensions and the intended joint spacing; check boundaries, niches, transitions, and trim. Do not infer a fixed waste percentage, allowable offset, or product compatibility from the pattern name.

Example: 10 × 12 Kitchen Area and Box Arithmetic

• Installed area: 10 × 12 = 120 sq ft.
• Illustrative 15% purchasing allowance: 120 × 1.15 = 138 sq ft, not a guaranteed allowance for a diagonal or other layout.
• At exact 12 × 24 inch dimensions: 138 ÷ 2 = 69 nominal tile-area equivalents.
• If a box contains 6 such tiles and its stated coverage is 12 sq ft: ceil(69 ÷ 6) = ceil(138 ÷ 12) = 12 boxes.
• Purchased quantity in this arithmetic example: 12 × 6 = 72 tiles, or 144 sq ft of face area.

This is purchasing math, not a layout or installation-material specification. Estimate grout and mortar from the 120 sq ft installed area and the actual joints, tile profile, and product data, not from the 138 sq ft allowance area or the 144 sq ft purchase. Round material packages only after calculating the product-specific requirement.

The Wet Slip Number a Tile Carton Can Carry

Nothing in this calculator's inputs tells you whether a tile is acceptable for a wet floor, but the industry does publish a number for it, and it appears in the documentation for many products. Daltile's published reading of the standard states: “ANSI A137.1 requires tile flooring products to have a DCOF of 0.42 or greater if recommended for use in a level interior space intended to be walked upon when wet. This specification is based on wet DCOF measurement performed according to ANSI A326.3.”

Read the clause narrowly: the threshold is for a level interior space intended to be walked upon when wet, and it is measured under ANSI A326.3 conditions — not a general “safe when wet” certificate. The same page is explicit about the limits: “ANSI A326.3 Wet DCOF measurements are based on specific standard practices under controlled conditions. These measurements provide useful information for comparison of product performance, but measurements should not be considered as an indicator of whether a slip can occur,” and “No floor tile is "slip proof."” It also names maintenance as a variable: “Improper maintenance and improper maintenance products can result in a build-up on the surface of the tile causing the tile to be slippery.”

Practical use: compare wet DCOF values between candidate products for a bathroom, entryway, or laundry, and ask the manufacturer for the value measured per ANSI A326.3 for the specific item and finish. That is a product-selection decision this area calculator cannot make for you.

Tile Size Changes the Wet Floor, Not Just the Tile Count

The nominal-equivalents table above shows what a size change does to a purchase: for 100 sq ft, 4 × 4 in needs 900 tile-area equivalents, 12 × 12 needs 100, and 12 × 24 needs 50. The same Daltile page links that choice to wet performance: “Tile size can be a factor for slip resistance in wet areas. Smaller sizes allow for more drainage through an increased number of grout joints and easier sloping. Planar variations on larger formats could result in a higher probability of standing water and increase the risk for hydroplaning.”

That is a second, independent reason sloped wet areas are usually tiled small: the grout joints are the drainage path, and the count column above is a direct proxy for how many joints you get per square foot — a 4 × 4 grid needs 900 pieces per 100 sq ft against 100 pieces of 12 × 12, and each additional row and column adds a joint line. A large format can still be right for a dry hall; it just needs its own decision rather than the wet area's number.

Cutting Tile Makes Respirable Crystalline Silica

Dry-cutting, chasing mortar, and grinding a slab all raise dust, and the particle size is what matters. OSHA's crystalline silica overview states: “Crystalline silica is a common mineral found in the earth's crust. Materials like sand, stone, concrete, and mortar contain crystalline silica,” and that respirable crystalline silica — “very small particles at least 100 times smaller than ordinary sand you might find on beaches and playgrounds” — “is created when cutting, sawing, grinding, drilling, and crushing stone, rock, concrete, brick, block, and mortar”. The same page reports that “About 2.3 million people in the U.S. are exposed to silica at work.”

Tile, thin-set mortar, and the concrete or brick beneath them are all on that list of materials, and a saw is on that list of operations. Two consequences for a tiling takeoff: wet cutting or dust collection is a line item rather than a preference, and the dust depends on the number of cuts, not the square footage. In the worked example above, 26 of the 54 positions are cut pieces (8 side-edge, 14 top/bottom-edge, 4 corner) — every one of those runs through a blade.

Tearing Out an Old Floor Has No Square-Footage Exemption

Removal is where the lead-paint rule bites hardest, because the minor-repair definition excludes certain methods regardless of size. 40 CFR 745.83 grants the 6 sq ft interior / 20 sq ft exterior boundary only to activities “where none of the work practices prohibited or restricted by § 745.85(a)(3) are used and where the work does not involve window replacement or demolition of painted surface areas”. Demolition of a painted surface area is outside the minor-repair category whatever its size — the same paragraph that lets a 2 × 3 ft patch through on area alone.

For a tile tear-out that means chipping mortar off a painted subfloor, or skimming a painted wall back to bare, is not something you can measure your way under 6 sq ft. And when painted components are removed, “the entire surface area removed is the amount of painted surface disturbed”, with jobs “performed in the same room within the same 30 days” counted as “the same job”. EPA's program page says who is bound — firms including sole proprietorships — while “In general, the RRP Rule does not apply to homeowners doing RRP projects in their own pre-1978 homes. However, it does apply if you rent all or part of your home, operate a childcare center in your home or if you buy, renovate and sell homes for profit (i.e., a house flipper).”

Frequently Asked Questions

Sources and How to Check This Page

• Daltile — DCOF AcuTest: slip-resistance testing and reading test results — the source of the DCOF quotations on this page, including “ANSI A137.1 requires tile flooring products to have a DCOF of 0.42 or greater if recommended for use in a level interior space intended to be walked upon when wet”, the “not an indicator of whether a slip can occur” limit, “No floor tile is "slip proof."”, and the tile-size/drainage paragraph. Fetched 2026-10-10. It is a manufacturer's reading of the ANSI standards, not the standard text itself; ANSI A137.1 and A326.3 must be purchased from the publishers.
• OSHA — Silica, Crystalline: Overview — the “earth's crust”, “cutting, sawing, grinding, drilling, and crushing” and “2.3 million people” statements are on that overview page. Fetched 2026-10-10. OSHA's standard itself is 29 CFR 1926.1153 for construction; this page quotes the overview only.
• 40 CFR § 745.83 — definitions for the Renovation, Repair and Painting rule — the “Minor repair and maintenance activities” paragraph carries the 6 / 20 sq ft limits, the demolition and window-replacement exclusions, the whole-component counting rule and the 30-day same-room rule. Fetched 2026-10-10.
• US EPA — Lead Renovation, Repair and Painting Program — the 1978 ban, the certification scope for firms, and the homeowner/rental/house-flipper sentence quoted above. Fetched 2026-10-10.
• The cut-plan arithmetic (103 = 7 × 12 + 2 × 9 + 8 × 0.125; 62 = 4 × 12 + 2 × 6.6875 + 5 × 0.125; 54 positions of which 26 are cut; the per-size equivalents in the table) is pure arithmetic on the stated dimensions — recompute it with a calculator, or rerun the widget with your own room.

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