Carpet Area Calculator
Add up the footwells, tunnel, and cargo floor as rectangles to get the total automotive carpet area, with a trim allowance built in.
Carpet area
Buy to the allowance figure, not the measured area — carpet is cut oversized and trimmed back to the pan, and moulded floors curve up the sills and tunnel.
Measuring a floor that isn’t flat
The reason a cabin always seems to need more carpet than the floor “looks like” is that the floor isn’t flat. It rises over the transmission tunnel, kicks up at the sills, and steps down into the footwells and cargo bay. Each of those faces has to be covered, so the real surface area is meaningfully larger than the plan-view footprint.
Splitting the floor into rectangles and measuring each along its contour captures that hidden area. Add a trim allowance because the carpet is fitted oversized and cut back in place, and you’ll order enough to finish the job without a second run to the supplier.
Frequently Asked Questions
How is the carpet area worked out?
Each floor section is a rectangle, so its area is length times width. The calculator sums every section you add, then adds your trim allowance on top to give the area to buy, shown in both square metres and square feet.
Why break the floor into sections?
A cabin floor isn't one flat rectangle — it's footwells, a raised transmission tunnel, sills, and a cargo area at different widths. Measuring each as its own rectangle and adding them up is far more accurate than trying to eyeball a single length and width for the whole floor.
What is the trim allowance for?
Automotive carpet — whether flat cut-pile or heat-moulded — is cut oversized and trimmed back to the floor pan after it's laid in, because it has to curve up the tunnel and sills. A 10–15% allowance covers that overlap and the offcuts; complex moulded floors want the higher end.
Should I measure over the tunnel and up the sills?
Yes. Follow the contour with a flexible tape rather than measuring the flat floor plan, because carpet has to cover the vertical faces of the tunnel and the kick-up at the sills. Those curves are exactly why the finished area is bigger than the floor looks from above.
Does this give an exact cut pattern?
No — it's a buying estimate, not a template. Use it to order enough material with margin to spare. For the actual cut, make paper or card patterns from the old carpet or the bare floor before you cut into new material.
Estimates for planning — not professional automotive or installation advice. Make patterns from your own floor before cutting into new carpet.