Quick brief
What to know before you calculate
A short read on the assumptions, trade-offs and definitions that shape the answer.
- Flooring is usually bought by pack, so final quantities need rounding up.
- Waste allowance depends on room shape, laying direction and pattern.
- Product pack coverage should be checked before ordering.
Calculate the main area
For a rectangular room, multiply length by width. Add extra areas for alcoves, thresholds or small connected spaces. If the room is irregular, split it into rectangles and add the areas together.
Use the pack coverage
Flooring products usually state coverage per pack. Divide the adjusted area by pack coverage, then round up to the next whole pack. Rounding matters because partial packs are rarely sold and mistakes are easier to fix when spare boards are available.
Set a waste allowance
Straight layouts in simple rooms often use around 10%. Diagonal laying, awkward shapes, herringbone patterns or many cuts can need more. Very small rooms can also have a higher waste percentage because offcuts are less reusable.
Plan for matching and repairs
Keep spare boards or tiles from the same batch if possible. They can be useful for future repairs, especially if the product range changes or the colour varies between manufacturing batches.
Related calculators
Try the numbers yourself
Open the calculators that match this topic and test the result with your own inputs.