Flooring & Tile Calculator

Work out how much laminate, vinyl plank or tile flooring to buy — by room, with waste for your layout, plus underlayment, trim, thinset and grout estimates and a cost estimate from your own price. Free, no sign-up, and your measurements stay in your browser.

Calculate your flooring

Enter positive numbers only. All coverage figures come from your product packaging — the calculator never invents a price or a coverage rate for you.

Units

Flooring type

Rooms

Product & layout

Plank length (inches)

Plank width (inches)

Coverage per box / pack (sq ft)

From the box or pack — check the packaging.

Layout

Waste allowance (%)

Straight 8–10%, diagonal 12–15%, herringbone about 20%. Changing the layout above sets this for you; adjust it if your rooms have many cuts.

Underlayment roll coverage (sq ft per roll)

Laminate and vinyl only — from the roll packaging.

Price per box / pack (optional — your price, in your currency)

Your estimate

How it works

Room area: for each room, length × width. Add the rooms together for the total area.
Add waste: multiply the total area by your waste allowance. Straight layouts need about 8–10% extra, diagonal layouts 12–15%, and herringbone about 20% — the extra covers cuts, damaged pieces and offcuts you cannot reuse.
Boxes or packs: divide the area including waste by the coverage of one box or pack, then round up to a whole box. You cannot buy part of a box, and rounding down would leave you short.
Planks or tiles: divide the area including waste by the area of one plank or tile, and round up.
Underlayment: divide the area including waste by one roll's coverage, and round up (laminate and vinyl only).
Trim / skirting: add up the perimeter of each room (2 × length + 2 × width), add about 10% for cuts and joins, and round up.
Tile extras: divide the area including waste by the coverage of one bag of thinset, and again by the coverage of one bag of grout. Both are approximate — trowel size, tile size and joint width change the real coverage, so use the figures on your bags.

Worked example

One room, 12 ft long by 15 ft wide, laminate flooring in a straight layout, boxes covering 20 sq ft each.

Room area: 12 × 15 = 180 sq ft
Add 10% waste for a straight layout: 180 × 1.10 = 198 sq ft
Boxes needed: 198 ÷ 20 = 9.9, rounded up = 10 boxes

So buy 10 boxes. If the same room were laid diagonally at 15% waste, it would be 180 × 1.15 = 207 sq ft, which is 207 ÷ 20 = 10.35, rounded up to 11 boxes.

Flooring needed by room size

Straight layout with 10% waste, boxes covering 20 sq ft each. Use the calculator above for your exact rooms, layout and box size.

Room size	Room area	Area with 10% waste	Boxes (20 sq ft each)
10 × 10 ft	100 sq ft	110 sq ft	6
10 × 12 ft	120 sq ft	132 sq ft	7
12 × 12 ft	144 sq ft	158.4 sq ft	8
12 × 15 ft	180 sq ft	198 sq ft	10
15 × 15 ft	225 sq ft	247.5 sq ft	13
15 × 20 ft	300 sq ft	330 sq ft	17
20 × 20 ft	400 sq ft	440 sq ft	22

Tile: thinset and grout guidance

Tile is set in thinset mortar and finished with grout, and both are bought by coverage, not by the tile count — so enter the coverage printed on each bag into the calculator. A few things that change how far a bag goes:

Trowel size: larger tiles need a larger notched trowel, which uses more thinset per square foot or square metre.
Tile size and joint width: small tiles and wide grout joints use more grout; large tiles with narrow joints use less.
Subfloor flatness: an uneven floor needs more thinset to level out. Fix dips and high spots first rather than trying to float them out with adhesive.
Spare tiles: buy a few spare tiles on top of the waste allowance — matching dye lots can be hard to find later if one cracks.

Thinset and grout figures from this calculator are approximate planning estimates. Follow the manufacturer's mixing and curing instructions on the bag.

Underlayment and trim

Underlayment: most laminate floors need it, and many vinyl plank floors do too — unless the planks already have an attached pad. It evens out small subfloor imperfections, softens sound and, in some products, adds a moisture barrier. Check your flooring manufacturer's instructions before skipping it, because the wrong underlayment (or none) can void a warranty.
Trim / skirting: the calculator totals the perimeter of your rooms and adds about 10% for cuts and joins. Measure doorways separately — you will need transition strips where the new floor meets another floor type, and door jambs may need undercutting.
Expansion gap: floating laminate and vinyl floors need a gap around the edges (check the manufacturer's instructions for the size). That gap is hidden by the skirting or trim, which is one more reason to measure trim properly.

What to buy — shopping list

Use the calculator's results as your list, and take it to the store:

Flooring — the number of boxes or packs shown, in your chosen type, size and colour (check the dye or batch number matches across boxes).
Underlayment rolls — for laminate and vinyl, if your product needs them.
Trim / skirting and transition strips — the length shown, plus a little extra for mistakes.
For tile: thinset bags, grout bags, spacers, and a few spare tiles.
Fixings and extras: adhesive or sealant if your product needs it, and a moisture barrier if the manufacturer or your subfloor calls for one.

Keep one spare box unopened if you can — most stores accept returns of unopened boxes, and a spare box is far cheaper than hunting for a matching batch later.

Frequently asked questions

How much extra flooring should I buy for waste?

As a planning estimate, allow 8–10% extra for a straight layout, 12–15% for a diagonal layout, and about 20% for a herringbone layout. Rooms with lots of corners, doorways or angles need the higher end of the range. This calculator applies 10% for straight, 15% for diagonal and 20% for herringbone by default, and you can adjust the waste percentage yourself.

How do I work out how many boxes of flooring I need?

Multiply each room's length by its width to get its area, add the areas together, add your waste percentage, then divide by the coverage printed on one box or pack and round up to a whole box. For example, a 12 by 15 ft room is 180 sq ft; with 10% waste that is 198 sq ft, so at 20 sq ft per box you need 10 boxes.

Do I need underlayment under laminate or vinyl plank flooring?

Most laminate and many vinyl plank floors need underlayment unless the planks already have an attached pad — check the manufacturer's instructions for your product. Tile does not use underlayment; it is set in thinset mortar on a suitable subfloor or backer board. This calculator estimates underlayment rolls for laminate and vinyl only.

How much thinset and grout do I need for tile?

Thinset and grout coverage depends on the trowel size, tile size and the product, so always use the coverage printed on the bag. As a rough planning figure, one bag of thinset often covers around 40–60 sq ft, but that is approximate — enter the coverage from your bag into the calculator for a better estimate.

Should I measure in feet or metres?

Use whichever you are comfortable with — the calculator works in feet (sq ft, boxes) or metres (sq m, packs). Just keep all measurements in the same unit, and check that your pack coverage is in the matching unit. Switching units in the calculator does not convert numbers you have already entered, so re-enter them in the new unit.

More calculators

Paint Calculator

Work out how much paint you need for walls and ceilings, with coats and coverage.

Concrete Calculator

Estimate concrete volume, bags and cost for slabs, footings and posts.

Moving Cost Calculator

Estimate the cost of your move by distance, home size and help needed.

Disclaimer: These are planning estimates only, based on the measurements and coverage figures you enter. Always check the manufacturer's instructions for your flooring, underlayment, thinset and grout, and measure twice before ordering. Subfloor problems, damp and moisture issues, and uneven or damaged floors need a professional — this calculator cannot assess the condition of your floor.