The number of stitches (tufts) per running inch of carpet usually is specified directly for tufted carpet, but is called rows per inch for woven carpet. The numerical product of tuft rows per inch of width multiplied by stitches per running inch is the number of tufts per square inch, or tuft density.

TARR Ratings Or Wear Ratings are ranked as Moderate, Heavy and Severe. These Classifications classify a carpet's ability based on foreseen recurrence and pedestrian activity. These ratings will aid in recognizing how well a specific carpet will perform in particular setting.

Fire Ratings The ASTM system classifies a carpet as Class 1 or Class 2, while the EN system is more stringent and detailed. With the EN system, letters A through F indicate how combustible the material is, with A being non-combustible to F being easily flammable.

Handily, household carpets in the UK are graded according to their durability: Light domestic – suitable for bedrooms. Medium domestic – suitable for dining rooms. General domestic – suitable for living rooms. Heavy domestic – suitable for stairs and hallways.