Kalkulačka Dlaždic – Kolik Dlaždic Budete Potřebovat?
Calculate exactly how many tiles you need for floor or wall projects. Enter your room dimensions, tile size, and grout joint width to get total tiles, boxes to purchase, and total project cost — with waste factor included.
Jak používat tuto kalkulačku
- Zadejte Room/Area Length (feet)
- Zadejte Room/Area Width (feet)
- Zadejte Tile Length (inches)
- Zadejte Tile Width (inches)
- Zadejte Grout Joint Width (inches)
- Klikněte na tlačítko Vypočítat
- Přečtěte si výsledek zobrazený pod kalkulačkou
How to Calculate How Many Tiles You Need
The basic tile calculation is straightforward:
- Calculate area: Room area = Length × Width (in square feet)
- Calculate tile area with grout: Tile area = (Tile length + grout width) × (Tile width + grout width) ÷ 144 (to convert to sq ft)
- Calculate tiles needed: Room area ÷ Tile area (per tile)
- Add waste: × (1 + waste percentage)
- Round up to whole tiles — always round up, never down
- Calculate boxes: ÷ tiles per box, round up
Never round down on tiles — running short in the middle of a project is a serious problem if tiles are discontinued or from a different dye lot.
Why Add a Waste Factor?
You always need more tiles than the raw square footage calculation suggests because:
- Cuts at edges: Perimeter tiles must be cut to fit the room boundary. Cut pieces generate waste (unusable offcuts).
- Breakage: Tile cuts inevitably break some pieces, especially thin tiles and diagonal cuts.
- Miscuts: Even experienced tilers make measuring and cutting errors.
- Future repairs: Keep 5–10% extra after installation for future replacements if one cracks.
- Layout adjustments: Sometimes tiles need to be repositioned, especially on walls.
Standard recommendation: 10% for straight layouts with simple rooms; 15% for average projects; 20–25% for diagonal layouts, herringbone patterns, or complex room shapes.
Common Tile Sizes and Where They're Used
| Tile Size | Common Uses | Tiles per sq ft |
|---|---|---|
| 12" × 12" | Floor standard, everywhere | 1.0 |
| 18" × 18" | Large floor areas, large rooms | 0.44 |
| 24" × 24" | Modern large-format, commercial | 0.25 |
| 6" × 6" | Bathroom floors, showers | 4.0 |
| 3" × 6" subway | Kitchen backsplash, walls | 8.0 |
| 4" × 4" | Classic bathroom walls | 9.0 |
| 12" × 24" | Modern large format plank style | 0.5 |
| 2" × 2" mosaic | Showers, decorative accents | 36.0 |
Choosing the Right Tile Size for Your Space
Tile size affects the perception of room size and complexity of installation:
- Small rooms: Large tiles (18"×18"+) can actually make a small room feel bigger by reducing grout lines; small tiles (4"×4") feel busy and busy can feel smaller
- Large rooms: Large format tiles (24"×24"+) look elegant but require a very flat subfloor and specialized setting materials
- The 1/3 rule: No tile should be cut to less than 1/3 of its original size at room edges — adjust layout starting point to achieve this
- Grout visibility: Smaller tiles = more grout lines = more visual activity = more maintenance
Grout Types and Selection
Choosing the right grout is as important as the tile itself:
- Sanded grout: For joints 1/8" or wider. Standard for floor tile. Provides strength and resistance to cracking in wider joints.
- Unsanded grout: For joints narrower than 1/8". Used for wall tile, glass tile, polished stone (sanded can scratch delicate surfaces).
- Epoxy grout: Highly stain-resistant, no sealing required, very durable. More expensive and harder to apply. Ideal for kitchen backsplashes and commercial applications.
- Grout amount: A 25-lb bag covers approximately 50–100 sq ft depending on tile and joint size.
Tile Setting Materials (Thinset)
Tiles are bonded using thinset mortar (cement-based adhesive). Coverage rates:
- Standard thinset (50 lb bag): covers ~40–50 sq ft for floor tile at 3/8" coverage depth
- For large format tile (18"×18" and larger): use medium-bed mortar, which provides more coverage thickness for back-buttering
- For mesh-backed mosaics: 1/8"–3/16" coverage; a 50-lb bag covers 80–100 sq ft
- White thinset: recommended under light-colored, translucent, or glass tiles
Subfloor Requirements for Tiling
Tile installation requires a solid, flat, stiff subfloor. The L/360 rule: deflection should not exceed the span divided by 360.
- Minimum subfloor thickness for tile: 1.5" total (typically 3/4" plywood + 1/2" cement board)
- Large format tile (18"×18"+): even stricter flatness requirements — no more than 1/8" variation over 10-foot span
- Concrete subfloor: excellent for tile — flat, check for cracks and moisture
- Radiant heat: use flexible uncoupling membrane (Schluter Ditra) and flexible thinset
Naposledy aktualizováno: March 2026
Frequently Asked Questions
How many 12×12 tiles do I need for 100 square feet?
For 100 sq ft with 12×12" tiles: 100 tiles exact, plus 10–15% waste = 110–115 tiles total. At 10 tiles per box = 11–12 boxes. Always round up to the next full box.
How do I calculate tiles for a bathroom floor?
Measure length × width = square footage. Example: 8×10 ft bathroom = 80 sq ft. Add 15% waste = 92 sq ft. Divide by tile size: 6×6" tile (0.25 sq ft) = 368 tiles. Then ÷ tiles per box to get boxes needed.
How much extra tile should I order?
Order 10–15% extra for standard straight-lay patterns. 15–20% for diagonal layouts. 20–25% for herringbone or complex patterns. Always keep 5–10 tiles after installation for future repairs — discontinued tiles are impossible to match later.
How do I account for grout lines in tile calculations?
Add the grout joint width to both dimensions of your tile for coverage area. For a 12" tile with 1/8" grout: effective tile coverage = (12+0.125) × (12+0.125) = 12.125² = 147 sq inches = 1.021 sq ft per tile (slightly more than 1.0 sq ft bare tile).
What is the best tile size for a small bathroom?
Counter-intuitively, larger tiles (12×12" or 12×24") can make a small bathroom look larger by reducing the number of grout lines. Traditional small tiles (4×4") create visual busyness. 12×24" rectangular tiles laid in a running bond pattern are a popular modern choice for small bathrooms.
How many boxes of tile do I need for 200 square feet?
It depends on tile size and tiles per box. For 12×12" tile (1 sq ft each): 200 tiles + 15% waste = 230 tiles. At 15 tiles per box = 16 boxes. At 10 tiles per box = 23 boxes. Use our calculator with your specific tile and box size for exact results.
Do I need to seal grout?
Sanded and unsanded cement grout should be sealed annually (or every 2 years) to resist staining. Epoxy grout doesn't need sealing. Use a penetrating grout sealer — spray-on types are easiest. Let grout cure fully (28 days) before sealing for best results.
What is a lippage in tile and how do I prevent it?
Lippage is height variation between adjacent tiles causing edges to be at different heights. Causes: unlevel subfloor, uneven thinset application, large-format tiles with bow/warp. Prevention: flat subfloor (within 1/8" per 10 feet), back-butter tiles, use leveling clips system for large format tile.
Can I tile over existing tile?
Yes, if existing tile is solid (no loose/hollow tiles), floor height allows (+1" for tile + mortar), and weight isn't excessive (especially on upper floors). Use a bonding primer and appropriate thinset. Note: this makes future removal much harder and significantly increases height.
How long does it take to tile a 100 sq ft room?
DIY: 1–2 days for experienced DIYers (day 1: prep and lay tile; day 2: grout and clean up). Professional: 4–8 hours per 100 sq ft floor. Add time for demo, subfloor prep, and difficult cuts. Bathroom shower walls add complexity and time.