The short answer
Grams per square metre is the weight of the carpet, and a higher figure usually means a denser, deeper pile that holds its shape longer. Sellers measure it on different bases, some counting the pile alone and some the whole construction, so a figure only compares grades within one seller's range. Where a set wears out first is almost always the driver's heel.
Key takeaways
- A heavier carpet is denser underfoot and keeps its look longer, all else being equal.
- Two sellers quoting the same number are not necessarily selling the same carpet.
- Published UK figures run from about 600 to over 3,000 g per square metre, which is too wide a spread to be one scale.
- The driver's mat wears out first, at the heel, long before the other three.
- A heel pad, and mats that are actually attached, add more life than an extra few hundred grams.
What the number means
Grams per square metre, written g/m2 or gsm, is how much a square metre of the carpet weighs. In practice it stands in for density: more material in the same area means a deeper, springier pile that recovers when you lift your foot and resists being crushed flat.
It says nothing on its own about the backing, the stitching, the binding around the edge, or whether the mat is cut to your car. A heavy carpet cut to the wrong shape is still the wrong mat.
Why you cannot compare between sellers
Published figures across UK sellers run from about 600 g/m2 at the entry end to over 3,000 at the top. That spread is too wide to be one measurement. Some quote the pile only, some the pile and its backing together, and almost nobody says which.
So use the number the way it is useful: to rank the grades within one range. Within one seller, 900 is denser than 600. Across two sellers, 900 and 600 tell you very little.
| What you are told | What it is good for | What it does not tell you |
|---|---|---|
| Weight in g/m2 | Ranking grades inside one range | How the carpet compares to another seller's |
| Pile height in mm | How deep it feels underfoot | How dense it is, and so how it wears |
| Material name, such as needle punch or tufted | How it is made, and roughly how it will look | How heavy or deep it is |
| Backing type | Whether it grips a carpeted floor | Anything about the top surface |
What actually decides how long a set lasts
Sets are rarely replaced because all four mats are finished. They are replaced because one is: the driver's, worn through where the heel rests while the foot pivots on the pedals.
- Heel wear. The same patch takes the load on every journey. A heel pad, a bonded panel in that spot, is the single most useful thing on a driver's mat.
- Grit. Sand and road grit cut fibres like sandpaper. Vacuuming often does more for a mat's life than anything else.
- Salt. Winter salt dries out and stiffens fibres, and leaves white marks behind. See car mats for winter.
- Movement. A mat that slides rubs against the car's own carpet and wears both. Fixings are there for a reason.
- Drying. Heat and direct sun make backings brittle. Mats dry best flat, out of the car, away from a radiator.
Choosing a grade without overthinking it
A lighter carpet is enough if
- The car is a second car or does short trips.
- Nobody wears work boots in it.
- You would rather spend the difference on a boot liner.
- You change mats every few years anyway.
Go heavier if
- You do high miles, or the car is a company car you want to hand back clean.
- The interior is light coloured, where crushed pile shows.
- You keep cars a long time.
- You want the mats to look like the ones the car came with, or better.
If the footwell gets genuinely wet or muddy, weight is the wrong question entirely. Carpet or rubber is the comparison that matters.
Shop the mats this guide covers
Common questions
Is a higher g/m2 always better?
Denser, yes. Better depends on the car and the use. A heavy carpet in a footwell that is regularly soaked is the wrong tool however good the carpet is.
Why does one seller's 1,500 feel thinner than another's 900?
Because they are not measuring the same thing. Some quote the pile alone and some the whole construction, and the basis is rarely published.
What is a heel pad?
A hard-wearing panel bonded to the driver's mat where the heel rests. It is the part that wears first, so protecting it extends the life of the set.
How long should a set last?
There is no honest single answer, because it depends on miles, footwear and whether the mats are fixed down. What is consistent is where they fail: the driver's heel area, first and by a distance.
Do you publish the weight of your carpets?
We will publish the figure our manufacturer gives us, with the basis it is measured on, once the ranges are confirmed. Until then we would rather say nothing than quote a number we cannot stand behind.
How we wrote this guide
The range of published figures comes from what UK sellers show on their own product pages, read in September 2026. None of them states the basis of measurement, which is why this guide treats the number as a within-range comparison rather than a specification.
Questions this guide does not answer? Write to us from the contact page.