Start with a rough sketch
Draw the outline, mark the direction of boards or paving, and write a unit next to every measurement. Measure at more than one position if walls or edges are not square. The calculators use decimal measurements: 10 feet 6 inches is 10.5 ft, not 10.6 ft.
Split an awkward space into rectangles
For an L-shaped floor, divide the shape into two rectangles that do not overlap. Multiply length by width for each and add the areas. A 4 m × 3 m section and a separate 2 m × 2 m section total 16 m². If the second section overlaps the first, subtract the overlap once.
You can estimate flooring packs from a combined area by using an equivalent rectangle, such as 16 m × 1 m, but the displayed perimeter will not be the real perimeter. Measure trim separately. Deck board layout and patio edging also need the actual shape; an area-only shortcut cannot give a reliable cut plan.
Check product sizes as well
Use the dimensions on the supplier’s specification. A nominal board name is not always the finished width. Flooring box coverage and paving pack sizes are product-specific. Photograph or write down the product code so your quote and calculation refer to the same material.
Make one final check
- Are all measurements in the same system?
- Have permanent uncovered areas been counted correctly?
- Is the board direction the intended one?
- Have you measured the sides that need edging or trim separately?