Is a 5m roll cheaper than a 4m roll for the same room?

Per square metre the price is usually similar; what changes is how much you have to order. A room 4.2m wide needs a seam or a lot of waste from a 4m roll but fits a 5m roll in one piece. A room 3.8m wide wastes very little from a 4m roll but leaves a 1.2m strip from a 5m roll. The cheaper width is the one whose strip your job can actually use.

How do I decide the roll width for a whole-house job?

Run the whole job as a cutting plan in both widths and compare the linear metres. The stairs and landing usually decide it: the width that leaves strips the stairs can be cut from wins. Cutting optimisation software does this comparison in seconds.

Trade guide

4m vs 5m carpet rolls: which width to order and when

Q: What widths do carpet rolls come in the UK?

The standard broadloom widths in the UK are 4m and 5m, with some products also made in 3.66m (12ft) and occasionally 2m for vinyl. Not every product comes in every width — many ranges are 4m-only, which removes the choice entirely.

Q: Should I avoid seams at all costs?

No — a well-placed seam in a doorway or under furniture is invisible and can save a large amount of material. The rule is that seams are placed deliberately at the planning stage, run with the pile, and never land in a window bay or main sight line. Sometimes two pieces with a good seam beat one oversized piece on both cost and appearance.

For UK flooring retailers and fitters · 7 minute read · Updated July 2026

Ask three fitters which roll width they prefer and you'll get habits, not arithmetic: "always 4m unless the room's huge", "5m saves seams", "whatever the supplier has in stock". All three habits are right on some jobs and expensive on others. The roll width is a per-job decision, and the deciding factors are only ever the same three: the room dimensions, where the offcut strips can go, and where a seam can acceptably sit.

The widths you're choosing between

UK broadloom carpet and sheet vinyl are overwhelmingly manufactured in 4m and 5m widths. Some ranges also come in 3.66m (the old 12ft), and vinyl in 2m. The first check is always the product itself: many ranges are 4m-only, and if so there's no decision to make — only a plan to optimise. Where a range does come in both widths, the m² price is usually similar; the money is in how many linear metres each width forces you to order.

The arithmetic that decides it

For a single room, compare the room's width against each roll width and look at two things: the strip left over, and whether a seam is needed at all.

Room width	From a 4m roll	From a 5m roll	Winner
3.4m	0.6m strip	1.6m strip	4m — unless the job needs that 1.6m strip
3.9m	0.1m strip — near perfect	1.1m strip	4m, clearly
4.2m	Seam needed (or turn the carpet)	0.8m strip	5m — one piece, and the strip suits stairs
4.8m	Seam needed	0.2m strip — near perfect	5m, clearly
5.4m	Seam needed	Seam needed	Either — plan the seam, compare totals

Two subtleties the table hides. First, length matters as much as width: a 0.8m strip beside a 6m-long room is nearly 5m² of carpet — a straight flight of stairs, as it happens. Second, pile direction limits your options: you can't always rotate a room to suit the roll, because pile must run consistently through the space and down the stairs, or adjacent pieces shade differently in daylight.

Seams versus waste: the real trade-off

The instinct to avoid seams is half right. A seam in the middle of a lounge floor, across the light from a bay window, is a callback waiting to happen. But a seam under a bed, along a hallway edge, or through a doorway is invisible — and choosing it can save several square metres of carpet. The professional approach is not "no seams" but "seams where I decided": placed with the pile, off the main sight lines, agreed with the customer where visible at all.

Rule of thumb: when a room just exceeds a roll width (say 4.1–4.3m against a 4m roll), don't default to the wider roll. Price both: the 5m roll in one piece, versus the 4m roll with a planned fill-strip seam along the least visible wall. On long rooms the seam option is often cheaper by a surprising margin.

Whole-house jobs: the stairs decide

On a multi-room job the question stops being "which width suits this room" and becomes "which width leaves strips the rest of the job can eat". Stairs and landings are the great consumers of strips: most UK domestic stairs are 0.8–0.9m wide, which is exactly what's left beside a 3.1–3.2m room on a 4m roll, or a 4.1–4.2m room on a 5m roll.

So run the whole job both ways. Nest every room, the stairs (measured properly — our stairs measuring guide covers winders and bullnoses) and the landing onto a 4m plan, then onto a 5m plan, and compare total linear metres × cost. The answer is frequently not the one habit would have picked, and the difference on a whole house is real money — see the ranges in our carpet wastage guide.

Vinyl: same logic, less forgiveness

Sheet vinyl follows the same width arithmetic with two twists: seams are less tolerated (water, welding, and they show more on hard surfaces), and pattern repeats on tile-effect and plank-effect vinyl mean cuts can only start at repeat intervals. Both push vinyl towards "one piece if humanly possible", which makes getting the width right even more valuable — a wrong-width vinyl order often can't be rescued with a seam the way carpet can.

Let the comparison be free

Doing this properly by hand — two full nested cutting plans per quote — is exactly the work that doesn't happen on a busy Saturday. It's also precisely what software is good at: testing both widths across thousands of arrangements and handing you the cheaper plan with the seams drawn in.

Run every job in both widths, automatically

PlanIt's roll cut optimiser nests the whole job across 4m and 5m rolls, respects pile direction, and shows the cutting plan and total metres for each — from £19 per user a month, with unlimited quotes.

Try the optimiser

Frequently asked questions

What widths do carpet rolls come in the UK?

4m and 5m are standard, with some ranges in 3.66m and vinyl also in 2m. Check the specific product first — many ranges are 4m-only.

Is 5m cheaper than 4m for the same room?

The m² price is usually similar; the total changes with how much each width forces you to order. The cheaper width is the one whose leftover strip your job can actually use.

Should I avoid seams at all costs?

No. A deliberately placed seam — doorway, under furniture, off the sight lines, running with the pile — is invisible and can beat an oversized single piece on cost and sometimes on appearance.

How do I decide the width on a whole house?

Plan the full job in both widths and compare linear metres. The stairs usually settle it: the width that leaves stair-sized strips wins.