How to use the flooring calculator
- Choose metric or imperial. Switching keeps your values and converts them.
- Add each room or area as a rectangle, measured wall to wall.
- Enter the coverage per box from the flooring label and a waste allowance.
- Optionally add a price per box, and tick “Include underlay” to count underlay rolls.
- Print the plan or save it in your browser.
How the estimate is worked out
- Floor area = length × width for each area, added together.
- Area to buy = floor area × (1 + waste allowance).
- Boxes = area to buy ÷ coverage per box, rounded up to a whole box.
- Underlay rolls = floor area ÷ coverage per roll, rounded up.
Worked example
A living room 5 × 4 m and a hall 3 × 1.2 m are getting laminate that covers 2.22 m² per box, with a 10% waste allowance.
- Floor area: 20 + 3.6 = 23.6 m². With 10% waste: 25.96 m².
- 25.96 ÷ 2.22 = 11.69, so you would buy 12 boxes (26.64 m²).
- Underlay in 15 m² rolls: 23.6 ÷ 15 = 1.57, so 2 rolls.
Choose Try an example above (with metric selected) to load these numbers.
Assumptions and limitations
- Areas are rectangles. Bay windows, curves and angled walls should be measured as the smallest rectangle around them.
- The waste allowance is a percentage of the floor area. It doesn’t model individual plank cuts or the stagger pattern.
- Coverage per box is taken from what you enter. The calculator doesn’t know any product’s sizes.
- Thresholds, door bars, scotia or quarter-round, adhesive and fixings are not included. The baseboard and skirting calculator can work out trim lengths.
Frequently asked questions
How much extra flooring should I buy?
For planks laid in straight rows, 5–10% extra is a common allowance. Rooms with lots of corners, doorways or alcoves need more. Diagonal laying and herringbone or chevron patterns usually need 15% or more. The flooring maker’s fitting instructions often give a figure, so use that if there is one.
Where do I find the coverage per box?
It is printed on the box label and the product page, usually as m² per pack or sq ft per carton. Use that figure rather than working it out from the plank size, because it already accounts for the tongue and groove.
How do I measure an L-shaped room?
Split it into two or more rectangles that don’t overlap, measure each one and add each as a separate area. Include the floor inside doorways where the new floor will run through.
Do I need underlay?
Most laminate and some engineered wood floors are laid on an underlay, unless the boards have one attached. Many vinyl and luxury vinyl tile products should not go on a soft underlay. Follow the flooring maker’s instructions.
Should I keep a spare box?
It is worth keeping any unopened box and a few spare planks. Batches can vary in colour, and the exact product may be discontinued by the time you need to repair a damaged board.
Last updated .