4x12 Tile Calculator
Your room, in 4 x 12 in tile
Picking a pattern sets the recommended waste factor.
Check the box label — it varies by brand.
Tiles to buy
396 tiles
- Area to cover
- 120 sq ft
- Area including waste
- 132 sq ft
- Tile size
- 4 x 12 in
- One tile covers
- 0.333 sq ft
- Boxes needed
- —
- Waste applied
- 10%
Tile is sold by the box — round up and keep one spare box from the same dye lot.
4 x 12 in tiles by room size
| Room | Area | Tiles (no waste) | With 10% waste | Grout | Thinset |
|---|---|---|---|---|---|
| Small bathroom (5 x 8) | 40 sq ft | 120 | 132 | 2.8 lb | 1 bag |
| Bathroom (8 x 10) | 80 sq ft | 240 | 264 | 5.6 lb | 2 bags |
| Kitchen (10 x 12) | 120 sq ft | 360 | 397 | 8.5 lb | 2 bags |
| Living room (12 x 15) | 180 sq ft | 540 | 594 | 12.7 lb | 3 bags |
| Open plan (20 x 20) | 400 sq ft | 1200 | 1320 | 28.2 lb | 6 bags |
Grout assumes a 1/16 inch joint and 3/8 inch thick tile. Thinset assumes a 1/4 x 3/8 inch square-notch trowel and 50 lb bags.
Why the size changes the job
Four by twelve covers a backsplash quickly, which is the point — but it also means a single cut tile at the end of a run is very visible. Set out the run dry first and split the difference between both ends.
Tile size drives three things people tend to discover late. It sets how much grout the floor needs — a 4 x 12 in field uses 7 lb of grout per 100 square feet at a typical joint, and smaller tile uses dramatically more. It sets how flat the subfloor has to be, because a rigid tile cannot follow a dip and a bigger tile spans more of one. And it sets which cutter you need: yours has to take the full 12 inch dimension.
Work the numbers with the grout calculator and the thinset calculator, and price the whole job with the tile cost calculator. If you have not measured yet, how to measure for tile covers the part that causes most over-ordering.
Other tile sizes
Closest in coverage to 4 x 12 in:
Do this math on the job site — in the free app
Smart Tile Calculator for Android: offline, in your pocket, no ads. iPhone version coming soon.
Tools the pros use for this job
Tile Spacers
500 Pcs 3 mm (1/8 Inch) Plastic Tile Spacers for Stone and Ceramic Tile | 500-Piece Pack,3 mm Spacing,Even Tile Layout,Plastic Construction,Multiple Installation Uses
Check price on AmazonConsistent joints are what make a 4 x 12 in layout read as deliberate rather than approximate.
Levelling System
Levelling System
Clips keep edges flush on an uneven subfloor, which is where small-format tile usually goes wrong.
View on AmazonClips keep edges flush on an uneven subfloor, which is where small-format tile usually goes wrong.
Tile Cutter
VEVOR Tile Cutter 48 in, Manual Cutting Machine, Heavy-Duty All-Steel Frame | For Precision Cutting of Porcelain, Ceramic, and Floor Tiles, with Laser Guide, Bonus Spare Cutter, and Manual Hand Tool
Check price on AmazonYour cutter has to take the full 12 inch dimension, or every cut becomes a two-pass job.
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How this calculator works
One 4 x 12 in tile covers 0.33 square feet. Divide your area by that figure, round up, then add waste. For 100 square feet that is 300 tiles before waste and 330 at 10 percent.
Four by twelve covers a backsplash quickly, which is the point — but it also means a single cut tile at the end of a run is very visible. Set out the run dry first and split the difference between both ends.
Order in boxes, not tiles. Box counts vary by manufacturer even at the same tile size, so check the square footage printed on the box and divide your total by that — then round up, because a shop will not sell you two thirds of a box.
Frequently asked questions
How many 4 x 12 in tiles do I need for 100 square feet?
300 tiles cover 100 square feet exactly, because each tile covers 0.33 sq ft. Order 330 to carry 10 percent waste, which covers the cuts at the edges and the few tiles you will break or reject. Keep the spares — matching a batch later is difficult and often impossible.
How many square feet is a 4 x 12 in tile?
0.33 square feet. The arithmetic is 4 times 12 divided by 144, since there are 144 square inches in a square foot. Nominal and actual sizes are usually the same for tile, unlike lumber, but a rectified tile can be a millimetre or two under its stated size — which matters over a long run.
What grout joint suits 4 x 12 in tile?
Around 1/16 inch is typical for this size. Joints under 1/8 inch need unsanded grout; 1/8 inch and wider need sanded. A rectified tile can take the tighter end of the range, a pressed tile with a slightly rounded edge needs the wider end to look even.
How much waste should I allow for 4 x 12 in tile?
Ten percent is the standard allowance for a straight layout in a simple rectangular room. Go to 15 percent for a diagonal layout, a room with several doorways or alcoves, or any pattern where an offcut cannot be reused on the next row.
Related calculators
- Tile Quantity CalculatorHow many tiles you need for any room, wall, or floor — with waste.
- Grout CalculatorPounds of grout by tile size, joint width, and thickness.
- Thinset & Mortar CalculatorBags of thinset by trowel notch size and coverage.
- Tile Cost EstimatorTotal project cost: tile, grout, mortar, trim, and labor.
Guides worth reading next
- How to Measure a Room for Tile (Step by Step)Measure any room for floor or wall tile: handle closets and alcoves, convert inches to decimals, subtract fixtures, and add the right waste percentage.
- Choosing the Right Tile Size for Your RoomHow tile size changes a room: when 12×24 beats 4×4, why small rooms can take large tile, grout line math, and the flatness rule for big formats.
- Sanded vs Unsanded vs Epoxy Grout: Which One Do You Need?Grout types explained by joint width and location: when sand scratches tile, why epoxy wins in showers, and how much of each type a bag actually covers.