Carpet Roll Width Planner Calculator

Planner Inputs

Room length (m)

Longest direction of the area you’ll cover.

Room width (m)

Shorter direction of the area you’ll cover.

Waste allowance (%)

Extra for trimming, errors, and offcuts.

Extra length allowance (cm)

Add for edges, tucks, or squaring.

Extra width allowance (cm)

Helpful for uneven borders and curves.

Seam allowance per seam (cm)

Overlap/trim room for joining strips.

Pattern repeat (cm)

0 means no pattern matching needed.

Roll width options (m)

2.00 m

2.50 m

3.00 m

3.66 m

4.00 m

5.00 m

Choose widths your supplier can provide.

Planning preference

Prefer fewer seams (better look, easier install)

If unchecked, the planner prioritizes lower waste when seam counts are similar.

Results appear above this form after you calculate.

Use case	Area (m)	Widths tested (m)	Typical pick	Why it works
Garden shed aisle runner	5.0 × 1.2	2.00, 2.50	2.00 m	Single strip, minimal trimming.
Patio seating rectangle	4.5 × 3.2	3.00, 3.66, 4.00	4.00 m	Fewer seams and simple cut plan.
Greenhouse work zone	7.0 × 3.8	3.00, 3.66, 4.00	3.66 m	Balances waste and seam count.

These are examples—your best roll width depends on the exact size and your chosen options.

Adjusted room dimensions = room dimension + allowance (converted from cm to m).
Strips needed = ceiling( span ÷ roll width ).
Seams = strips − 1.
Pattern adjustment: strip length is rounded up to the next pattern repeat.
Waste allowance: ordered strip length = strip length × (1 + waste% / 100).
Total linear meters = strips × ordered strip length.
Ordered area = total linear meters × roll width.
Waste area = ordered area − room area.

The planner evaluates each roll width in both orientations, then ranks results using your preference (fewer seams) and waste.

For complex shapes, split the project into rectangles and run the planner for each section.