The Laminate Floor Calculator calculates how many boxes of laminate flooring and how many rolls of underlayment you need for a room.
It multiplies length by width for the floor area, adds your waste allowance and divides by the coverage per box. Underlayment is calculated on the floor area itself, divided by the coverage of one roll.
Laminate Floor Calculator
Boxes of laminate flooring and rolls of underlayment for a room, with waste.
Formula
- Boxes: ⌈L × W × (1 + waste %) ÷ box coverage⌉
- Underlayment rolls: ⌈L × W ÷ roll coverage⌉
- Laminate to order: L × W × (1 + waste %)
How the Calculation Works
Step 1: Find the floor area.
Step 2: Add waste and divide by the box coverage.
Step 3: Divide the floor area by the underlayment roll coverage (set it to 0 if your laminate has attached padding).
Variables Explained
| Input | Meaning |
|---|---|
| Coverage per box | Square feet in one carton |
| Underlayment roll coverage | Square feet one roll covers |
| Waste allowance | Extra for cuts and mistakes |
Example Calculation
Given: room 15 × 12 ft, 20 ft² per box, 10% waste, 100 ft² underlayment rolls
Area: 180 ft²; to order: 198 ft²
Boxes: 198 ÷ 20 → 10
Underlayment: 180 ÷ 100 → 2 rolls
Common Area Conversion Table
| Unit | Equivalent |
|---|---|
| 1 m² | 10.7639 ft² |
| 1 yd² | 9 ft² |
Material Estimation Notes
- Underlayment seams are usually butted or overlapped per the product instructions; if yours overlaps, allow extra.
- Laminate is a floating floor, so leave an expansion gap at the walls; baseboard or quarter-round covers it.
- Transition strips, moisture barrier (on concrete) and trim are separate.
Waste Factor Considerations
The right allowance depends on plank length, the room’s shape and whether you lay planks straight or diagonally. Offcuts from one row can often start the next, which reduces waste in simple rooms.
Frequently Asked Questions
How many boxes of laminate do I need?
Floor area plus waste, divided by the box coverage.
How much underlayment do I need?
Floor area ÷ roll coverage, rounded up.
Do I need underlayment if my laminate has a pad?
Follow the manufacturer’s instructions; set roll coverage to 0 to skip it.
How do I plan the first and last rows?
Use the Laminate Floor Layout Calculator.
Should I buy an extra box?
Many people keep spare planks for repairs.
