About the Flooring Calculator
Buying too little flooring means a second trip and a risk of mismatched batches, while buying too much wastes money. This calculator turns a room's length and width into a floor area, adds a waste allowance for cuts and mistakes, and divides by the area one box covers to give the number of whole boxes to buy. It also shows how much flooring will be left over and, if you enter the price per box, the total cost. Use it for laminate, vinyl planks, engineered wood, carpet tiles or ceramic tiles, in metres or feet.
Updated October 2026
How to use the Flooring Calculator
- 1Pick metres or feet, and your currency.
- 2Enter the length and width of the room.
- 3Choose a waste allowance. 10 percent suits most rooms.
- 4Enter how much area one box covers, from the label or product page.
- 5Read the number of boxes, the spare flooring and the cost.
Choosing your waste allowance
Waste comes from cutting planks to fit around walls, trimming the last row, working around pipes and bad pieces. Straight layouts in square rooms waste the least. Diagonal layouts waste more because every plank is cut at an angle. Patterned tiles that must match need extra to line up.
If you are inexperienced, add a few percent more to cover mistakes. You can usually return unopened boxes, so check the shop's policy.
Think about the direction of the planks and the room's longest sight line before you buy. Laying boards along the longest wall or toward the main light source usually looks best, but it can change how many full boards you use at the ends of the rows. If the last row would be narrower than about 5 cm, plan to trim the first row too so both edges look balanced. Cutting these narrow rows is the main source of waste, which is why the percentage you choose matters.
Measuring tips
- Measure twice and write the numbers down.
- Include closets and recesses that will have flooring.
- Leave out fixed units like kitchen cabinets if they sit on the floor.
- Keep a 8 to 10 mm expansion gap at the walls for floating floors.
- Let the boxes sit in the room for 48 hours before laying them.
Other planning tools
For ceramic and stone tiles use the Tile Calculator, which handles tile size and grout gaps. The Area Calculator finds the area of unusual shapes, the Paint Calculator covers the walls and the Wallpaper Calculator helps with wall coverings. The Unit Converter switches between square metres and square feet.
Features
- Boxes rounded up to whole packs
- Waste allowance you control
- Spare flooring after the job
- Total cost from a price per box
- Square metres or square feet
- Works for any flooring that comes in boxes
Frequently asked questions
How much extra flooring should I buy?
Most fitters allow 10 percent for a standard straight layout. Use 5 percent in a simple rectangular room, 15 percent for diagonal layouts or patterned tiles, and up to 20 percent for herringbone or rooms with many corners and alcoves.
How do I measure a room for flooring?
Measure the length and width at the longest and widest points, ignoring door recesses for now. Multiply them for the area. For an L-shaped room, split it into rectangles, calculate each area and add them together.
Why do boxes cover odd areas like 2.2 square metres?
Planks and tiles are packed in whole pieces, so a box covers the sum of those pieces, such as 2.22 square metres. Always use the coverage printed on the box, not the number of planks times a guessed size.
Should I buy one extra box?
Many people do, especially for floors that may need repairs later. Manufacturers change shades between batches, so a spare box from the same batch can save a mismatched patch years later.
Does the calculator include underlay or skirting?
No. It covers the floor surface only. Underlay is bought by the same area, usually with its own waste allowance. Skirting boards and trims are measured by their length around the room.
Can I use it for carpet?
Carpet comes in rolls of fixed width, so the calculation differs. This calculator suits carpet tiles, which come in boxes, but not broadloom carpet.