Free Floor Area calculator with clear step-by-step results.
Adds a rectangular alcove or bay to the main room area so irregular rooms can be measured without a plan, then converts to packs including cutting waste. The perimeter figure is included because trim is bought by the metre and is easy to forget until the floor is down.
Net area
Area = main length x main width + alcove length x alcove width
Packs required
Packs = ceil(net area x (1 + waste) / coverage per pack)
Ten percent for a straight-laid rectangular room, 15% if laying diagonally or into a room with many recesses, and more for a herringbone pattern.
One spare pack is worth having. Batch shading varies between production runs, so a later replacement for a damaged board may not match.