TOOL_04 · Flooring & Walls
Tile calculator
Boxes to buy, tile counts, and grout needed — with cut waste factored in. Never run short on the same dye lot.
① Room & tile sizes
Boxes to order
0boxes
Based on 10 sq ft/box packaging
Total tiles needed
0tiles
12" × 12" tile size
Order area (with waste)
0sq ft
Net room: 120 sq ft + 10% extra
Grout needed
0lbs
Estimated for standard 1/8″ joint
Material Cost Estimator
Estimated Total for Tile Boxes
$336.00
14 units × $24.00 per box
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How the math works
Net area: Room length × room width = square footage.
Waste factor: Net square footage is multiplied by 1.10 (+10% for straight lay) or 1.15 to 1.20 (+15% to 20% for diagonal, herringbone, or complex shapes).
Boxes to order: Total area with waste divided by the square feet per box specified by the manufacturer, rounded up to the nearest whole unopened box.
Pro tip: Save an extra box
Tiles are produced in specific manufacturing dye lots. If you need repairs or pipe replacements years later, matching the exact color is nearly impossible. Keep one extra unopened box in your attic or basement.
Frequently asked questions
- How much extra tile should I buy for waste and cuts?
- Standard straight-lay tile installations require a 10% overage factor for cuts, edge trim, and accidental breakage. For diagonal installations, herringbone patterns, or rooms with lots of corners and obstacles, plan on 15% to 20% waste.
- How do I calculate how many boxes of tile I need?
- Multiply your room length by width to get total square footage, multiply by 1.10 (for 10% waste), and divide by the square footage printed on your specific tile box (typically 10 to 15 sq ft per box). Always round UP to the nearest whole box so you don't run short or mix dye lots later.
- How many tiles are in a square foot?
- For standard 12" × 12" tiles, exactly 1 tile equals 1 square foot. For 12" × 24" tiles, each tile covers 2 square feet (so 0.5 tiles per sq ft). For 6" × 24" plank tiles, each tile covers 1 square foot. For 4" × 12" subway tiles, you need 3 tiles per square foot.
- How much grout do I need?
- For standard 12" × 12" floor tiles with a standard 1/8" grout joint, plan on approximately 8 to 10 lbs of dry grout powder per 100 square feet. Smaller tiles like mosaic or subway tile have significantly more joints and can require 12 to 15 lbs per 100 sq ft.