Math Calculators
Flooring Calculator
Flooring is sold by the pack and underlay by the roll, so one calculation turns a room into both. This calculator finds the floor area, adds your wastage allowance once, divides by one plank and by one pack's coverage for the packs, and counts the underlay rolls. The tile count stays on the tile calculator, linked here.
Calculator
Formulas
Floor area = length × width, or the area entered directly. Area with wastage = floor area × (1 + wastage ÷ 100). Planks = area with wastage ÷ (plank length × plank width), rounded up. Packs = area with wastage ÷ coverage of one pack, rounded up. Underlay rolls = floor area ÷ coverage of one roll, rounded up — the wastage allowance is not added to the underlay, because it buys planks for offcuts, not membrane for the floor.
About This Calculator
What It Does
This calculator turns a room into the quantities a flooring order needs. Enter the room's length and width, or the floor area as a total, and set a wastage allowance for offcuts and the last row. Then state the plank you are buying — two sides, with the unit — the floor area one pack of that plank covers, and the area one roll of underlay covers. It returns the floor area in both square feet and square metres, the area with the allowance added once, the planks and the packs to buy rounded up to whole units, and the rolls of underlay for the same floor.
Worked Example
A room 12 ft × 10 ft is 120 sq ft, or 11.15 m². With a 10% allowance the floor to cover is 132 sq ft, or 12.26 m². A 1210 mm × 190 mm plank covers 0.23 m², so 12.26 ÷ 0.23 = 54 planks. The packs cover 2.2 m² each, so 12.26 ÷ 2.2 = 5.57, rounded up to 6 packs. A 15 m² roll of underlay covers the 11.15 m² floor in one roll.
Real-World Usage
Use it before ordering laminate, engineered wood, vinyl or any pack-sold board: it gives the packs to carry home and the planks they contain. The underlay count is for the same floor, so a membrane order can be placed at the same time. Change the plank size or the pack coverage to compare two products on the same room.
Local Context
Packs are labelled in square metres in most of Europe and in square feet in the United States, and plank sizes are stated in millimetres, centimetres or inches — the calculator takes any of them and reports both area systems. No tax, delivery or threshold rule is applied: the quantities are the material only, and the merchant's own coverage figure on the pack is the one to trust.
Last reviewed: November 2026.
For guidance only. Check the coverage printed on the pack and the roll before ordering, and allow for doorways, alcoves and cutting waste.
Frequently Asked Questions
How much wastage should I allow for flooring?
A straight lay in a rectangular room usually takes 5% to 7%; a diagonal lay, a herringbone, or a room with many alcoves and doorways takes 10% or more. The allowance is added to the area once, and both the plank and the pack count are read from that same area.
Should I buy packs or planks?
Packs, in practice: a pack is the unit the shop sells and the calculator rounds the pack count up, so the last pack covers the offcuts. The plank count is the same area divided by one plank, which tells you how many boards the packs contain.
Does the calculator work out the tile count?
No. Tiles are counted on the tile calculator, which takes a tile's size, a grout gap and tiles per box. This page answers the plank and pack question and the underlay beneath it; the two pages link to each other.
How much underlay do I need?
The underlay is fitted to the floor before the boards go down, so it is counted from the floor area, not from the area with the plank wastage. Count one roll per 15 m² (about 160 sq ft) of floor, or whatever your roll states, and add a lap allowance if the product asks for one.
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