Carpet Padding Calculator
Room area + padding type → padding rolls and total weight needed.
Result
- Floor area200 ft²
- Padding typeRebond 6 lb/ft³
- Standard thickness7/16" (~11 mm)
- Density × thickness0.219 lb/ft²
- Area with waste220 ft²
- Total weight48.1 lb
- Roll width6 ft
- Linear ft needed37 lft
- Rolls (30-ft length)2
Step-by-step
- Area with waste = 200 × 1.10 = 220.0 ft².
- Weight = 220.0 × 6 lb/ft³ × 0.0365 ft = 48.13 lb.
- Linear ft = area / roll-width = 220.0 / 6 = 37 lft.
How to use this calculator
- Enter room area in ft².
- Pick padding type — 6-lb rebond is the residential standard.
- Set roll width (6 ft common; 12 ft for commercial).
- Read linear ft, roll count, and total weight.
About this calculator
Carpet padding (cushion) is sold by linear foot of a fixed-width roll. The Carpet & Rug Institute (CRI) standard for residential bedrooms is 6-lb density rebond at 7/16" thick; stair and commercial applications use higher density (8-lb) or rubber-slab. The pad transfers wear off the carpet backing and meaningfully extends carpet life — CRI estimates carpet life roughly doubles with proper-density pad versus none or under-density.
What this calculator does
This calculator converts a room's floor area into the padding rolls (in linear feet and 30-ft roll count) and total padding weight needed. Density and standard thickness vary by padding type — rebond at the residential 6 lb/ft³ and premium 8 lb/ft³ levels, memory foam, synthetic fiber, and rubber slab for commercial. Output is the actual purchase quantity (with a configurable waste factor) and the total weight you'll be carrying upstairs.
How it works — the formula
area_with_waste = area × (1 + waste)
weight_lb = area_with_waste × density (lb/ft³) × thickness (ft)
linear_ft = ⌈area_with_waste / roll_width⌉Weight per ft² is density × thickness. CRI standardizes pad thickness at 7/16" and publishes the density ladder for residential and commercial use. Roll width is set by the manufacturer (4, 6, or 12 ft commonly); linear feet is the purchase unit.
Worked examples
- Inputs:
- area=200, type=rebond-6, rollW=6, waste=10%
- Output:
- 37 linear ft (2 × 30-ft rolls); ~36 lb
Standard residential bedroom installation.
- Inputs:
- area=400, type=rebond-8, rollW=6, waste=10%
- Output:
- 74 linear ft (3 × 30-ft rolls); ~96 lb
Higher-density pad recommended for higher-traffic areas.
- Inputs:
- area=1000, type=rubber, rollW=12, waste=10%
- Output:
- 92 linear ft (4 × 30-ft rolls); ~882 lb
Commercial-grade rubber for high-traffic offices.
When to use this vs other tools
Use this when planning a carpet installation. For other floor materials (hardwood, vinyl), the dedicated tools handle their respective math.
- Hardwood Planks
Use for solid or engineered hardwood plank counts and waste factor.
- Vinyl / Laminate Flooring
Use for LVT, sheet vinyl, or laminate floor materials estimating.
Authority note
CRI is the US trade association for the carpet industry and publishes the cushion-density standards adopted by every major carpet manufacturer's warranty. Density and thickness figures used here come from CRI 105.
Limitations
- Standard thickness 7/16"; thinner pad (3/8") is used for some commercial loop carpet — re-check manufacturer spec.
- Pad rolls are typically 30 ft; some come in 60-ft for commercial.
- Doesn't account for stair pad (sold separately, often denser).
- Tackless strip and seam tape are additional accessories not counted here.
Check carpet manufacturer warranty for pad density and thickness requirements — using out-of-spec pad voids most warranties.