Flooring Calculator

How this calculator works

The calculator divides your floor area by the area one plank covers, then adds a wastage allowance for cuts and rounds up to whole planks (and boxes):

planks = ceil( room length × room width ÷ (plank length × plank width) × wastage )

If you only know the coverage printed on the box rather than a single plank size, enter a plank length and width that multiply to that coverage. All math runs in exact metric internally, so switching feet and metres never changes the result.

Worked example

This example follows the unit system you pick in the calculator above.

A 5 m × 4 m room, 1200 mm × 190 mm planks, 10% wastage, 8 planks per box:

1. Floor area: 5 × 4 = 20 m².
2. Each plank covers 1.2 × 0.19 = 0.228 m².
3. 20 ÷ 0.228 ≈ 88 → with 10%: ≈ 97 planks.
4. At 8 per box: ceil(97 ÷ 8) = 13 boxes.

The extra planks cover the offcut at the end of each row - which becomes the starter for the next row - plus breakages and a spare or two for repairs.

Choosing the right wastage allowance

Rooms with bay windows, alcoves, kitchen islands or many doorways sit at the high end of each range.

Laminate, vinyl plank and hardwood

The calculation is the same for any plank floor - area ÷ plank coverage + wastage - but the details differ by material:

• Laminate - sold in boxes by coverage (often about 2 m² / 20 sq ft per box). Floating click-lock planks that need underlay and an 8–10 mm expansion gap. Use 5–10% wastage.
• Vinyl plank (LVP / luxury vinyl) - click or glue-down planks with the box coverage on the label, often with underlay pre-attached. Use 5–10% wastage, toward 10% for long planks in long rooms.
• Hardwood and engineered wood - sold by the box or pack, with boards of varying length, so open several packs and blend as you lay. Use 5% in a square room, 10%+ for diagonal or herringbone, and keep spares from the same batch.

Enter your plank size - or your box coverage entered as a single plank - and the calculator handles all three the same way.

Tips for measuring

• Let the floor run into doorways and under the threshold - measure to the centre of each doorway.
• Buy every box from the same batch and check the batch number; shade varies between runs.
• Lay planks from several boxes at once to blend any colour variation across the floor.
• Keep one full plank back for repairs - matching a discontinued floor years later is hard.

Trim and pack sizes where you are

In the United Kingdom, the expansion gap around the perimeter is hidden by the skirting board, and flooring is sold by the pack, labelled in square metres - often around 1.8-2.5 m² per pack. Enter that box or pack coverage as a single plank size in the calculator above and it works out the packs to buy.