Flooring & Tile Calculator
Add up the rooms, pick the material and the layout, and get the square footage, the waste allowance, the exact number of boxes to buy and what the floor costs.
Instant answers
Works offline once loaded
Nothing you type is sent anywhere
Any number of areas
Rounded to whole boxes
Layout-aware waste
Areas to floor
Break the space into rectangles. Use the − button on a row to subtract it instead — an island, a hearth, a stair opening.
Layout
Picking a layout above sets this; override it if you know your room.
Printed on the carton. 0 if you are buying by the square foot.
Buy this much flooring
—
Net floor area—
In square metres—
In square yards—
With waste allowance—
Boxes to buy—
Spare left over—
Material cost—
Cost per square foot laid—
The rest of the job
Leave at 0 to use the room perimeters.
| Item | Quantity | Unit price | Cost |
|---|
Grout and tile layout
For tile only — how many tiles cover the area, and how much grout the joints take.
Tiles needed (with waste)—
Tiles per square foot—
Grout volume—
Thinset mortar—
Instructions
How to use this calculator
Step by step
- Break the space into rectangles and enter each one as a row. An L-shaped room is two rectangles; a room with a bay is the main rectangle plus the bay.
- Use the + / − button on a row to switch it between adding and subtracting. Subtract kitchen islands, hearths, stair openings and built-in cabinets that the floor does not run under.
- Pick the layout. Straight runs waste the least; diagonal and herringbone waste more because every board at the edge is cut at an angle and the offcut is unusable.
- Enter the coverage printed on the carton — most laminate and vinyl plank boxes are between 18 and 25 square feet. Set it to 0 if the material is sold loose by the square foot.
- Read the buy figure. It is always a whole number of boxes, because that is what the shop will sell you, and the spare figure below tells you how much you will have left.
- Fill in the underlay and trim to get a full bill of materials and a real cost per finished square foot.
- For tile, put the tile size and grout joint into the last panel to get the tile count, the grout weight and the thinset bags.
Good to know
- Keep one full box back after the job. Colour lots change, and a plank damaged in three years is unfixable without a spare.
- Measure at the widest point of each rectangle. Rooms are rarely square, and the floor has to reach the far wall at its worst point.
- Ten percent waste is right for a straight lay in a simple rectangular room. Add five for a room with lots of doorways, closets or angles, and go to twenty for herringbone or any diagonal pattern.
- Short boards are not waste until they are shorter than your minimum end-piece length — usually 8 to 12 inches. Starting each row with the offcut from the last is what keeps the real waste near the estimate.
- Acclimatise wood and laminate in the room for 48 hours before laying it. It is the single most common cause of gaps and buckling later.
- Buy grout and thinset from the same batch as well — grout colour varies more between lots than most people expect.
The maths behind it
- Net area Σ (length × width) added − Σ subtracted Rectangles added and removed to describe an irregular floor.
- With waste area × (1 + waste %) The waste covers cuts, damage and pattern matching.
- Boxes ceil(area with waste ÷ coverage per box) Always rounded up — boxes are not sold in halves.
- Tiles area ÷ ((w + joint) × (l + joint) ÷ 144) The joint is part of the space each tile occupies, so it belongs in the tile footprint.
- Square metres sq ft × 0.092903 Exact conversion.
- Square yards sq ft ÷ 9 Carpet is still often sold this way.
How much waste should I allow?
Ten percent for a straight lay in a plain rectangular room, fifteen for a diagonal lay or a room with many corners and doorways, and twenty for herringbone or chevron. If the material has a strong pattern that has to be matched across seams, add five more. Waste is the cheapest insurance in the job.
Should I round up to whole boxes?
You have no choice — retailers sell flooring by the carton. This calculator does the rounding for you and reports how much spare that leaves. If the rounding leaves you barely over, consider buying one more box anyway; a single damaged plank can otherwise stop the job.
Do I subtract the kitchen island?
Only if the floor does not run underneath it. Many installers run the floor under fixed cabinetry anyway, both because it is faster and because it means the room can be reconfigured later. If yours is going under, leave the island in.
Why is the tile count higher than the area divided by the tile size?
Because each tile occupies its own size plus one grout joint on two of its sides. With a 12 × 24 in tile and a 1/8 in joint, each tile really takes up 12.125 × 24.125 in of floor. Over a large area that difference is a couple of percent — enough to matter when you are ordering.
Does this work for carpet?
For the area and cost, yes. Carpet is different in one important way: it comes on a roll of fixed width, usually 12 ft, so the real waste depends on how your rooms fit that width rather than on a percentage. Use the square yard figure here as your starting point and let the supplier work out the roll plan.
What is a realistic total cost per square foot?
The bill of materials here covers flooring, underlay and trim only. Professional installation typically adds $2–$6 per square foot depending on the material and whether the old floor has to come up. The cost-per-square-foot figure this page reports is materials laid, not the finished job.