About this calculator
This calculator helps estimate how much roll flooring (linoleum, vinyl, or carpet) a room needs — choose the room shape (rectangle, one of four non-rectangular templates, or a freely sketched shape), enter the roll width and the laying direction. Unlike tile or laminate calculators, the central question here isn't area, but how strips lay out across the roll width and how many seams result between them.
Formula
The room shape is entered through the shared roomShape field, the same five-template
(rectangle, L, alcove, T, U) plus free-form mechanism as the floor-tile calculator. But it
is used differently here: strip layout is always computed from the shape's own
bounding box, not the true polygon outline — see the explanation below and Assumptions
and limits. From the bounding box, the calculator picks which dimension is the "run"
(strip direction) and which is the "across" dimension (the one strips are stacked along,
side by side):
strip length = run dimension + pattern repeat
strip count = ceil(across dimension / roll width)
seam count = strip count - 1
base length required = strip count × strip length
waste length = ceil(base length × waste% / 100)
total length required = base length + waste length
Each strip is cut independently to the full required length — offcuts between strips are not reused (not pieced together like a mosaic). This matches the wallpaper calculator's own logic: patterned material needs each strip's start aligned to the pattern repeat, so a shorter offcut can't start the next strip; for unpatterned material this is a conservative assumption, since the real possibility of reusing offcuts depends on the room's actual geometry, which a bounding box alone doesn't capture. The calculator also shows a warning if the opposite laying direction (strips running along the other dimension) would produce fewer seams than the one chosen.
room area (and, with it, waste area) is computed from the true area of the chosen
shape's polygon, not the bounding box — so for an L, T, U, or alcove-shaped room the waste
area shows more waste, not a shorter required roll length (see Assumptions and limits for
why this is a deliberate decision, not a bug).
Worked example
Defaults: room shape — rectangle 5 × 4 m (the template's own default dimensions), roll width 2 m, pattern repeat 0 mm, laying direction — along the length, waste 5%.
run dimension (along the length) = 5000 mm, across dimension = 4000 mm
strip length = 5000 mm + 0 mm = 5000 mm
strip count = ceil(4000 / 2000) = 2
seam count = 2 - 1 = 1
base length = 2 × 5000 mm = 10,000 mm
waste length = ceil(10,000 × 5 / 100) = 500 mm
total length required = 10,000 + 500 = 10,500 mm = 10.5 m
room area = 5 m × 4 m = 20 m²
purchased flooring area = 2 m × 10.5 m = 21 m²
waste area = 21 m² - 20 m² = 1 m²
For these inputs the calculator returns exactly this: a required roll length of 10.5 m, 2 strips, 1 seam, and 1 m² of waste area.
FAQ
Why does the calculator ask for a laying direction, rather than just the area? Roll flooring is bought by length, not area — the strip count and seam count depend on which room dimension you choose as the strip direction. The calculator compares both directions and warns if the chosen one produces more seams than the alternative.
Are offcuts between strips reused? No. Each strip is cut independently to the full required length — no offcut is carried over to start another strip. This applies equally to patterned and plain material.
How much waste should be allowed for roll flooring? The default is 5%, adjustable from 0 to 30. The real requirement depends on how regular the room shape is, seam matching, and edge trimming.
Why do I need to enter a pattern repeat? If the flooring (usually carpet) has a pattern, each strip's start needs to align with the previous one — that adds one repeat step to the strip length. For plain linoleum or vinyl with no pattern, leave this at 0.
What determines the roll width? Roll width is a value you enter — it's printed on the specific product you've chosen and is commonly 2, 3, or 4 metres, but varies by manufacturer and flooring type.
Why doesn't the strip count go down for an L, T, U, or alcove-shaped room, compared with a rectangular room the same size as the shape's bounding box? Because roll flooring is physically laid by rolling a strip straight across the whole room in one direction, then trimming away whatever falls outside the true room footprint — a notch (an alcove or a corner) never shortens the required roll length, it only adds waste. That's why strip layout in this calculator is deliberately computed from the shape's bounding box, not the true outline — this is NOT a limitation or an approximation error, it is the correct model of how the material is physically laid. Room area and waste area are, at the same time, computed from the true outline, so a notch still correctly shows up as more waste.
Assumptions and limits
No standard was found for roll width, pattern-matching allowance, or waste rate — these
depend on the specific product, so meta.standards is deliberately left empty.
Strip layout is deliberately computed from the room shape's own bounding box, not the
true polygon outline — even for a non-rectangular template. This reflects how roll
flooring is actually laid: a strip is rolled straight across the whole room, and whatever
falls outside the true room footprint (a niche, a notch) is simply trimmed off and
discarded — a notch never shortens the strip or seam count, it only adds waste. room area
(and, with it, waste area) is computed from the true polygon area, so a notched (L, T, U,
alcove) room correctly shows more waste, not a shorter required roll length. If this
assumption seems surprising on first reading the result — it is a deliberate modeling
decision, not a bug.
Offcut reuse between strips is not modeled — each strip is cut independently to the full required length, with no credit for a previous strip's leftover. This matches the same assumption the wallpaper calculator makes for its own strips.
Roll width and pattern repeat are user inputs with example (not product-specific) defaults — your chosen flooring's exact figures must be entered. The drawing is schematic: for a very wide room laid from a narrow roll, the seam-line count is decimated so the SVG stays legible.