Floor Area
Free Floor Area calculator with clear step-by-step results.
About Floor Area
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.
Formulas
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)
Worked example
With the default values below, Floor Area returns Net floor area of 24.84. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Main room lengthminimum 0.1 m
- 5.4 m
- Main room widthminimum 0.1 m
- 4.2 m
- Alcove or bay lengthminimum 0 m
- 1.8 m
- Alcove or bay widthminimum 0 m
- 1.2 m
- Cutting wasteaccepts 0–40 %
- 10 %
- Coverage per packminimum 0.1 m2
- 2.2 m2
Results
- Net floor area
- 24.84 m2
- Area to order including waste
- 27.32 m2
- Packs to buy
- 13 packs
- Perimeter for skirting or beading
- 19.20 m
Step by step
- 1Values used
- 2Net area
- 3Packs required
- 4Net floor area= 24.84 m2
- 5Area to order including waste= 27.32 m2
- 6Packs to buy= 13 packs
- 7Perimeter for skirting or beading= 19.20 m
Assumptions and limits
- The result is derived only from the 6 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How much waste should I allow?
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.
Should I order a spare pack?
One spare pack is worth having. Batch shading varies between production runs, so a later replacement for a damaged board may not match.