How Much Carpet Do I Need?
Quick Answer
Approximately 14m² of carpet for a 4m × 3.5m room
Based on: 4m × 3.5m room, standard 4m roll width, allowing for fitting waste
How We Calculated This
- Room: 4m × 3.5m = 14m²
- Roll width: 4m (covers the room width in one piece)
- Length needed from roll: 3.5m + 100mm trimming = 3.6m
- Carpet purchased: 4m × 3.6m = 14.4m²
Standard UK Roll Widths
- 4m (13ft): Most common for domestic carpet
- 5m (16ft): Available in premium ranges
- 2m (6ft 6in): Budget ranges, stair carpet
Fitting Direction Matters
Carpet should ideally run towards the main light source (usually the window) to reduce the visibility of seams. Your fitter will advise on the most economical cutting plan to minimise waste, especially in L-shaped rooms or hallways with stairs.
What Else You Need
- Underlay: Same area as carpet. 8–11mm thickness for most domestic use
- Gripper rods: Room perimeter minus doorways. Standard 1.2m lengths
- Door bars/threshold strips: One per doorway
- Carpet tape: For seams if the room is wider than the roll
Last updated: April 2026