Flooring Calculator: How Many Tiles or Boxes for a Room

What it calculates

For a rectangular room and a chosen tile or plank size, the calculator gives:

• the floor area in square feet and square metres;
• the number of pieces to order, including wastage for the laying pattern;
• the number of boxes, rounded up to whole boxes;
• the skirting run, with door openings left out.

It works for vitrified and ceramic tiles, carpet tiles, and vinyl or wooden planks: anything sold as pieces of a fixed size.

Inputs

Room length and room width are the inside dimensions of the room, in feet.

Tile or plank length and width are the nominal size of one piece, in millimetres: 600 × 600 for a 2 ft vitrified tile, 500 × 500 for most carpet tiles, and the plank size from the product for vinyl or wood.

Pieces in a box is printed on the box label or the product datasheet.

Laying pattern sets the wastage: straight lay, diagonal or brick-bond, or herringbone and chevron.

The assumptions panel holds the wastage percentage itself and the total width of door openings left out of the skirting.

Method

1. Floor area = length × width, converted to square metres.
2. Area to order = floor area × (1 + wastage).
3. Pieces = area to order ÷ area of one piece, rounded up.
4. Boxes = pieces ÷ pieces in a box, rounded up.
5. Skirting = 2 × (length + width) − door openings.

Assumptions

Wastage figures are planning allowances. Rooms with many corners, columns, ducts or built-in furniture produce more cut pieces; large-format tiles produce more waste per cut.

Limitations

• Rectangular rooms only. Split other shapes into rectangles and add the results.
• No allowance for fixed furniture or kitchen units. If flooring stops at fitted furniture, measure the floor that will actually be covered.
• It does not set out the floor. Where the first tile starts decides how big the cut pieces at the walls are, which affects both looks and waste.
• It does not include adhesive, grout or underlay. Those follow the product's own coverage figures.
• Batch and shade. Order the whole quantity, spares included, from one batch.

Worked example

A 30 ft × 20 ft room, 600 × 600 mm vitrified tiles in boxes of 4, laid straight:

The order is 163 tiles in 41 boxes. Laid diagonally instead, at 10% wastage, the same room needs 171 tiles in 43 boxes.

How engineers use it

A site engineer or quantity surveyor works from the floor finish drawing rather than a single rectangle: each finish area is measured separately, wastage is applied by pattern and room shape, and the setting-out point is fixed before ordering so that cut pieces at doorways and along the main walls are a sensible size. The take-off also covers the items this calculator leaves out: adhesive, grout, levelling, underlay, transition strips and skirting.

When a professional design must replace it

Use the calculator to estimate quantities, compare tile sizes and check a supplier's quotation. Replace it with a measured take-off from the finish drawings before a large order is placed, especially where several finishes meet, the floor has a pattern, or the room is irregular. Where the floor needs levelling or waterproofing first, that work is specified and measured separately.