Underlayment Calculator
Calculate underlayment rolls and adhesive tape needed for laminate, vinyl plank, or engineered hardwood flooring.
Results
Visualization
How It Works
Underlayment is a thin layer between subfloor and floating floor. It provides sound dampening, moisture protection, and smooths minor subfloor imperfections.
The Formula
Rolls = CEIL(Room Area x 1.10 overlap / Roll Coverage)
Variables
- Overlap — 10% extra for edge overlap between rows
- Roll Coverage — 100-200 sq ft per roll depending on type
Example
200 sq ft room with standard foam: 200 x 1.10 = 220 sq ft / 200 per roll = 2 rolls.
Tips
- Skip underlayment if your flooring has it pre-attached — doubling up causes problems.
- Use a vapor barrier type on concrete subfloors to prevent moisture damage.
- Cork underlayment provides the best sound reduction but costs 2-3x more.
- Overlap seams by 4-6 inches and tape with underlayment seam tape.