ToolNestFree Tile Calculator
Last updated: October 26, 2026
Quick answer: Ordering tile is the one home-improvement purchase where guessing wrong costs you twice: order short and the second batch arrives a shade off — or discontinued — and order long and you have paid for boxes you will never open. This free tile calculator does the ordering math properly: enter your room size (or your total area), your tile size, and your grout joint, and it returns the tiles you need, the tiles to buy with waste, the boxes to order, the spare tiles left over, and the estimated cost. Unlike most thin calculators, it counts the grout joint as part of each tile's footprint — a 1/8-inch joint on 12-inch tile changes the count by about 2% — and it lets you set waste by layout, because a herringbone floor genuinely wastes more tile than a straight one. Everything runs in your browser; no signup, no app.
Order rule that saves remodels: buy all boxes from one production lot. Dye lots vary visibly between runs, and a second order months later is how bathrooms end up with two shades of "the same" tile.
✓ Free forever · ✓ No signup · ✓ Tool inputs stay in your browser — never sent to our servers.
How to Use the Tile Calculator
- Choose how to start: the usual case is room length × width (12 ft × 10 ft), but if you already measured the area — say a 120 sq ft floor, or several rooms added together — switch to total area and enter it directly. For L-shaped rooms, split them into rectangles, run each through the calculator, and add the tile counts.
- Pick your tile size from the presets (12×12, 18×18, 24×24, 12×24, 6×6, 4×4, 3×6 subway) or choose custom size and enter the tile's width and length in inches. The size that matters is the tile's face size — the number on the box — not the box's coverage claim, which already bakes in its own waste guess.
- Set the grout joint: 1/16 inch for rectified (machine-cut) tile, 1/8 inch for standard wall and floor tile, 3/16 or 1/4 inch for rustic and large-format tile. The calculator adds the joint to each tile's footprint, because the joint is real area: a 1/8-inch joint on 12-inch tile makes each tile cover 1.021 sq ft, not 1.000.
- Set waste by layout, not by habit: 5% only for a simple rectangle laid straight, 10% as the standard for most rooms, 15% for diagonal layouts or rooms with many cuts around fixtures, 20% for herringbone or complex patterns. Waste is the offcuts at the edges, the tile you drop, and the spares you will want in five years when a tile cracks.
- Enter tiles per box (printed on the box, or count one open box) and, if you know it, the price per box. Press Calculate tiles and read five numbers: area, tiles with no waste, tiles to buy with waste, boxes to order, and spares left over — plus the estimated tile cost when you entered a price.
- Press Copy order to take the order to your notes or to the tile shop. Buy the whole order in one lot: dye lots vary noticeably between production runs, and a second batch can arrive a visible shade off.
Why Use Our Tile Calculator?
- Grout-joint-aware math — the joint is added to each tile's footprint before dividing, so the count reflects what you will actually lay. Most thin calculators divide by the bare tile size and quietly under-order by 2–4%.
- Two starting points — room dimensions for the usual case, or total area when you have already measured, or when you are tiling several rooms and want one combined order.
- Waste by layout — straight, diagonal, and herringbone presets (5–20%) instead of one fixed 10% guess, because pattern complexity is the single biggest driver of how much tile you actually waste.
- Boxes and spares, not just tiles — suppliers sell by the box, so the result rounds up to whole boxes and tells you how many spare tiles that leaves you, which is the number you will be glad of when one tile cracks in year three.
- Cost line when you want it — enter a price per box and the estimate appears beside the box count, so the material budget is settled before you talk to an installer.
- Subway and custom sizes included — the 3×6 subway preset handles backsplash math (hundreds of small tiles, where the joint matters most), and custom size covers any tile the presets don't.
Common Use Cases
- A 12×10 ft kitchen floor in 12×12 tile: 120 sq ft, 1/8-inch joint, 10% waste: 130 tiles, 13 boxes at 10 per box, no spares left over — which is the signal to add one box if this tile is a fashion color. The joint-aware count (130) versus the naive count (132) is a two-tile difference here; on a whole house it is a box or two.
- A subway-tile backsplash: A 10 ft × 2 ft backsplash is 20 sq ft. In 3×6 subway with a 1/8-inch joint and 15% waste: each tile covers 0.133 sq ft, the exact count is 150.5 tiles, the order is 174 tiles. Small tile means big counts — this is the job where guessing ('a few boxes') goes wrong fastest, and where the joint matters most.
- Checking a contractor's tile bid: A bid that allows 20% overage on a plain rectangular kitchen is padding the order; a bid that allows 0% waste on a herringbone bathroom is going to run short mid-job. Run the room here with the honest waste for the layout and compare the bid's tile allowance against it before you sign.
- Tiling two rooms from one order: A 120 sq ft kitchen plus a 60 sq ft entry is 180 sq ft total — use total-area mode once instead of two separate orders, so the box rounding happens once and you buy from a single lot. One lot, one shade, one delivery.
Tile Calculator vs Alternatives
- Thin single-input tile calculators (most of the current top 10): They answer the basic question — area ÷ tile size — with a clean page. What they do not do is count the grout joint, offer waste by layout, or report spares, so the number they give is close but not the order. This page adds the joint, layout-based waste, boxes, spares, and cost in one place.
- Tile shop coverage charts: The box's coverage claim ('covers 10 sq ft') is a useful shortcut, but it bakes in the manufacturer's own waste guess and ignores your joint and layout. Use it to sanity-check the calculator's box count, not to replace it — if they disagree by more than a box, trust the calculator's joint-and-layout math and ask the shop why.
- Spreadsheet tile estimators: Serious remodelers keep a spreadsheet with area, joint, waste, and box rounding, and it is the best tool once your rooms are settled — this page prints the same five numbers on every result so you can build yours. A spreadsheet does not help the first time, though: it needs the joint rule and the waste-by-layout figures, which is what this calculator supplies.
- Woodworking cut-list optimizer (ToolNest's companion tool): That tool answers the material question for lumber: how to cut boards with the least waste. If your question is tile — joints, boxes, spares — this tile calculator is the right one; if your question is boards, use the cut-list optimizer.
Most tile calculators give you a tile count and stop. This page gives you the order: joint-aware count, waste by layout, boxes, spares, and cost — the five numbers you actually hand to the tile shop.
Frequently Asked Questions
How many tiles do I need for a 12×10 ft room?
With 12×12-inch tile, a 1/8-inch grout joint, and 10% waste: the room is 120 sq ft, each tile covers (12.125 × 12.125) ÷ 144 = 1.021 sq ft, so the exact count is 117.5 tiles and the order is 130 tiles (117.5 × 1.10, rounded up). At 10 tiles per box that is 13 boxes. Enter your own numbers above — the joint and the waste percentage move the answer more than most people expect.
How do you calculate how many tiles you need?
Tiles = area ÷ effective tile area, then add waste and round up. Area is length × width in feet. Effective tile area is (tile width + grout joint) × (tile length + grout joint), converted from square inches to square feet by dividing by 144. Then: tiles to buy = ceiling(exact tiles × (1 + waste %)). If the supplier sells by the box, boxes = ceiling(tiles to buy ÷ tiles per box). The calculator above does all four steps.
What waste percentage should I add for tiles?
10% is the working standard for a straight lay in a normal room. Use 5% only for a simple rectangle with almost no cuts. Use 15% for a diagonal layout or a room with many cuts around toilets, tubs, and doorways. Use 20% for herringbone, chevron, or a room with many corners and obstacles. Waste is not padding for the shop's benefit — it is the offcuts at every edge, breakage, and the spares you need when a tile cracks years later and the line is discontinued.
Do grout joints really change the tile count?
Yes, and more than intuition suggests. A 1/8-inch joint on 12-inch tile adds about 2% to each tile's footprint, which removes about 2% from the count — 130 tiles instead of 132 on a 120 sq ft floor at 10% waste. On small tile the effect is bigger: a 1/8-inch joint on 3×6 subway tile adds about 6% to each tile's footprint. Calculators that ignore the joint systematically over-order on small tile and under-order on nothing — the joint only ever shrinks the count, so ignoring it inflates it slightly. Either way, the joint belongs in the math.
How many boxes of tile do I need?
Boxes = ceiling(tiles to buy ÷ tiles per box). Tiles per box is printed on the box — it varies by size (a box of 12×12 might hold 10, a box of 24×24 might hold 4). Always round up to whole boxes: suppliers do not split boxes, and the spare tiles are your future repair stock. The calculator shows the spare count so you can see exactly what rounding up leaves you.
How many tiles do I need for a bathroom floor vs a backsplash?
The math is identical; the waste is not. A bathroom floor (say 5×8 ft = 40 sq ft) in 12×12 tile at 10% waste needs about 44 tiles, but the cuts around the toilet flange, tub, and vanity often push it toward 15% waste. A backsplash is measured in square feet of wall (length × height, minus windows), and subway tile at 15% waste is normal because every outlet cut wastes a tile. Measure the wall, subtract nothing for outlets — the waste allowance covers them — and use the total-area mode for the whole backsplash.
Should I buy extra tiles beyond the waste allowance?
The waste allowance already includes spares, but one extra box beyond the calculated order is cheap insurance if your tile is a fashion color or a small-batch line: discontinued lines are the number-one reason remodelers cannot match a cracked tile. If the tile is a standard white subway that will be stocked for a decade, the calculated order plus its spares is enough. Either way, keep the spares in the original box, labeled, in a dry place.
How much does it cost to tile a floor?
Material cost = boxes × price per box, which the calculator gives you when you enter a price. Tile itself runs roughly $1–$3 per sq ft for budget, $3–$8 for mid-range, and $8–$30+ for premium or large-format. Grout runs about $18–$30 per 25 lb bag, thinset about $15–$25 per 50 lb bag (one bag covers roughly 40–50 sq ft). Professional installation typically adds $5–$15 per sq ft on top. The calculator's cost line covers tile only — add grout, thinset, and labor for the full job budget.