🏠 Flooring Calculator PRO
Multi-room flooring with per-room floor type, pattern waste, underlayment, adhesive, grout, transition strips, and trim.
Dimension Diagram — first room, updates as you type
Floor area plus pattern waste decides boxes; underlayment follows the same area.
1 Floor Areas
2 Underlayment
3 Adhesive & Grout
Grout (Tile Rooms)
4 Transition Strips & Trim
5 Pricing & Labour
Labour Cost
Results
Area
Material Breakdown
Per-Room Summary
⚠️ Pre-Export Checklist
- All room dimensions verified on-site
- Subfloor condition inspected
- Floor types confirmed per room
- Installation pattern selected and approved
- Underlayment type chosen for each floor type
- Transition strips measured between rooms
- Expansion gaps planned at walls
- Material quantities verified before ordering
Professional Flooring Installation Guide
Show formulas, patterns, and worked examples ▼
Formulas
Floor Area= Length × Width per room
Area with Waste= Area × (1 + Pattern Waste%)
Pattern Waste:Straight = 5%, Diagonal = 10%, Herringbone = 15%, Chevron = 12%, Basketweave = 10%
Underlayment Bags = Total Area ÷ Coverage (sqft/bag)
Adhesive Bags = Total Area ÷ Trowel Coverage
Grout Bags= Tile Area ÷ 40 sqft/bag
Tiles Needed= Area with Waste ÷ Tile Size (sqft/tile)
Worked Example
Living Room 15×12, Herringbone hardwood + Kitchen 10×8, Straight tile:
- Living Room: 180 sqft × 1.15 (herringbone 15%) = 207 sqft
- Kitchen: 80 sqft × 1.05 (straight 5%) = 84 sqft
- Total with waste: 291 sqft
- Underlayment (100 sqft/bag): 3 bags
- Adhesive (3/8" trowel, ~45 sqft/bag): 7 bags
- Grout (kitchen tile, ~40 sqft/bag): 3 bags
Pattern Guide
- Straight (5% waste): Standard parallel layout — minimal cuts, easiest install
- Diagonal (10% waste): 45° to walls — makes rooms look larger, more edge waste
- Herringbone (15% waste): V-shaped interlocking — classic look, highest waste due to many cuts
- Chevron (12% waste): Continuous V-pattern — similar to herringbone but with angled ends
- Basketweave (10% waste): Alternating blocks — decorative, moderate waste
Floor Type Notes
- Hardwood: Requires foam or cork underlayment. Moisture barrier for concrete slabs. Expansion gaps essential.
- Laminate: Always needs underlayment. Foam is standard. Use moisture barrier over concrete.
- Vinyl (LVP/LVT): Many include attached pad. If not, thin foam underlayment. No moisture barrier needed for most.
- Ceramic/Porcelain Tile: Needs mortar (thin-set) and grout. Cement backer board on wood subfloors.
- Carpet: Requires pad underlayment. Transition strips at doorways. Stretch-in or glue-down method.
- Natural Stone: Must use modified thin-set. Seal stone AND grout. Heavier — may need subfloor reinforcement.
Common Mistakes to Avoid
- Using wrong waste factor for pattern — herringbone needs 15%, not 5%
- Skipping underlayment — voids laminate warranty and causes noise
- Wrong trowel size — too small = poor adhesion, too large = excessive squeeze-out
- No expansion gaps — wood and laminate need 1/4" to 1/2" gap at walls
- Forgetting transition strips — different floor heights between rooms need proper transitions
- Not sealing grout — unsealed grout stains easily, especially in kitchens and bathrooms
Professional Tips
- Acclimate hardwood and laminate 48-72 hours before installation
- Dry-lay tiles first to plan cuts and minimize waste on complex patterns
- Large format tiles (12×24+) require flat subfloor — use self-leveling compound
- Use modified thin-set for porcelain and natural stone, unmodified for basic ceramic
- Overlap moisture barrier seams by 6 inches and tape
- Plan material purchases with 5-10% buffer beyond calculated amounts
Drag to rotate — Scroll to zoom
関連する計算機
Frequently used together on the same project.
Client & Quote (prints on PDF & Excel)
Adjustments (applies to exports)
Contingency is added as a separate line on the exported cost summary. Waste % is printed as an advisory reminder.
Project notes (prints on PDF & Excel)
Result compare (A/B)
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Saved rates auto-apply from your Price Library. Advanced details stay in your browser — nothing is uploaded except inside your own PDF/Excel exports.
Choosing and installing flooring is one of the most visible upgrades you can make to a home, but miscalculating tile, adhesive, or grout quantities leads to wasted material and frustrating delays. Our free online flooring calculator eliminates the guesswork by computing the exact number of tiles, bags of thinset adhesive, and grout needed for any room.
Simply enter the room length and width, select your tile size, and specify the grout joint width. The calculator accounts for a standard waste factor to cover cuts, breakage, and pattern matching. It converts the total area into individual tile counts, then calculates thinset requirements based on coverage rates. Contractors use this tool to prepare accurate bid sheets, and homeowners appreciate the cost breakdown.
📖 この床計算機の使い方
Step 1: Measure the Floor
Enter the length and width of the area to be tiled. For L-shaped rooms, break into rectangles and add the areas together.
Step 2: Select Tile Size
Choose from common sizes: 12x12, 12x24, 18x18, or 24x24 inches.
Step 3: Set Grout Joint Width
Typical grout joints range from 1/16 inch for rectified tiles to 3/8 inch for handmade tiles.
Step 4: Enter Waste Percentage
Standard waste is 10% for simple layouts. For diagonal patterns or herringbone, use 15 to 20%.
Step 5: Enter Material Costs
Input price per square foot for tile, price per bag for thinset and grout.
Step 6: Review Results
The output shows total area with waste, number of tiles, bags of thinset, pounds of grout, and total cost.
📐 床カバレッジの計算式
The basic flooring formula is Total Tiles = (Area + Waste) / Tile Area. For a room measuring 8 ft by 10 ft using 12x12 inch tiles, the floor area is 80 square feet. With 10% waste for cuts and breakage, you need 88 square feet of tile.
Thinset adhesive coverage depends on trowel notch size. A 1/4-inch square-notch trowel applies approximately 50 square feet of coverage per 50-pound bag. For our 88-square-foot job, you need 88 / 50 = 1.76 bags, which rounds to 2 bags.
Grout volume is calculated from the tile dimensions, joint width, and total area. The cost calculation multiplies tile count by per-tile price, then adds thinset and grout costs for a complete material budget.
⚠️ 避けたいよくあるミス
Not ordering enough waste for cuts
✓ Simple straight layouts need 10% waste. Diagonal patterns need 15 to 20%. Herringbone and custom borders need 20 to 25%.
Ignoring tile lippage on large-format tiles
✓ Tiles over 15 inches require a flatter subfloor (3/16 inch in 10 feet). Large tiles on an uneven floor create dangerous lippage.
Using the wrong trowel size
✓ Larger tiles need larger notch trowels to achieve adequate adhesive coverage.
Not letting thinset cure before grouting
✓ Walk on tiles after 24 hours but wait 48 to 72 hours before grouting.
💡 プロのヒント
Acclimate tile to the room temperature for 24 hours before installation.
Check the floor flatness with a 6-foot straightedge before starting.
Mix thinset to peanut-butter consistency and let it slake for 10 minutes before remixing.
Work in small sections and back-butter large tiles to ensure 95 percent adhesive coverage.
❓ よくある質問
For 100 square feet with 10% waste, you need 110 tiles. Always buy a few extra for future repairs.
A 50-pound bag of thinset covers approximately 40 to 60 square feet depending on trowel size.
Tile can be installed over vinyl, concrete, or existing tile if the surface is flat, clean, and structurally sound.
You can walk on tile after 24 hours, but avoid heavy traffic for 48 hours. Wait 48 to 72 hours before grouting.
🏗️ 実際の用途
Flooring estimation directly impacts project budgets because tile, adhesive, and grout add up quickly. A typical bathroom floor at 50 square feet uses about 55 tiles, 2 bags of thinset, and 10 pounds of grout. For a full-house tiling project covering 1,200 square feet, the material quantities scale significantly.
Contractors use this tool during the bidding phase to generate accurate takeoffs. For commercial projects like retail stores and restaurants, flooring quantities can be thousands of square feet and estimation errors have significant cost implications.
Our free flooring calculator is the most accurate online tool for estimating tile count, thinset adhesive, grout quantity, and flooring material costs. Get accurate material lists and cost breakdowns before purchasing tile.
✅Method, Sources & Review
Maintained by theBuildingCalc methods desk· Last reviewedSeptember 23, 2026. This calculator implements the standards and references below; every figure can be rechecked against the formulas and worked example on this page.
Results are estimates, not engineering advice. Verify against local codes and licensed professionals for structural, electrical, and gas work. See ourTerms. Spotted an error? Report it— corrections ship with the next review.