The Laminate Floor Layout Calculator tells you how many rows of planks fit across a room and how wide the first and last rows should be.
It subtracts the expansion gap at each wall from the room width, divides by the plank’s face width to count rows, and checks the width left for the last row. If the last row would be narrower than one-third of a plank, it splits the difference so the first and last rows are equal.
Laminate Floor Layout Calculator
Rows of laminate planks, and how wide to rip the first and last rows so neither is too narrow.
Formula
- Net width: Wₙ = W − 2 × gap
- Rows: n = ⌈Wₙ ÷ p⌉
- Last row (unbalanced): Wₙ − (n − 1) × p
- If the last row < p ÷ 3: first and last rows = (last row + p) ÷ 2
Where W = room width across the planks, p = plank face width, gap = expansion gap at each wall.
How the Calculation Works
Step 1: Subtract the expansion gaps from the room width.
Step 2: Count how many rows of planks fit, rounding up.
Step 3: If the final row is too thin, rip the first row too so both are equal.
Variables Explained
| Input | Meaning |
|---|---|
| Room width | Measured across the direction the planks run |
| Plank face width | Visible width once installed (excluding the tongue) |
| Expansion gap | Gap left at each wall (per manufacturer) |
Example Calculation
Given: room 150 in wide, 7½ in planks, ⅜ in gap each side
Net width: 150 − 0.75 = 149.25 in
Rows: 149.25 ÷ 7.5 = 19.9 → 20
Last row: 149.25 − 19 × 7.5 = 6.75 in — wide enough, so the first row stays a full 7.5 in
When balancing is needed
If the last row came out at 1.5 in, both first and last rows would be ripped to (1.5 + 7.5) ÷ 2 = 4.5 in.
Dimensions Explained
Measure in several places
Walls are rarely perfectly straight. Measure the room width at both ends and in the middle; if they differ, scribe the first row to the wall.
Expansion gap
Laminate is a floating floor that moves with humidity; use the gap your manufacturer specifies and cover it with baseboard or quarter-round.
Material Estimation Notes
For the number of boxes, use the Laminate Floor Calculator. Stagger end joints between rows as the manufacturer recommends.
Frequently Asked Questions
How wide should the first row of laminate be?
Full width unless the last row would be too narrow; then rip both to equal widths.
How do I calculate the last row of laminate?
Net room width minus (rows − 1) × plank width.
What if my last row is only an inch wide?
Split the difference with the first row so both are wider.
Do I measure plank width with the tongue?
No — use the visible face width.
Which direction should laminate run?
Often parallel to the longest wall or main light source; it’s a design choice.
