Flooring Calculator

Estimate how many boxes of flooring to buy — with the right waste for your layout.

Flooring for a 12 × 15 ft room, laminate.

You need10boxes

Grab 1 extra box (11 total) as attic stock for future repairs.

Laminate
20 sq ft/box
10% waste (straight rows)
underlayment needed

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See the full breakdown

Floor area: 180.00 sq ft
With 10% waste (straight rows): 198.00 sq ft
Box coverage: 20 sq ft/box
Boxes to buy: 10
With 1 spare box (attic stock): 11 boxes
That many boxes cover: 200.00 sq ft
Underlayment (floating floor): 180.00 sq ft

How this is calculated

Floor area = length × width (feet).
Waste: +10% for a straight rows layout — diagonal and herringbone cut more, so they waste more.
Box coverage: Laminate is typically ~20 sq ft/box. Coverage varies by product, so override it with your box's actual figure.
Attic stock: buy 1 extra box (11 total) and keep it sealed — dye lots change, so a future repair rarely matches new stock.
Floating floor: budget underlayment for the same square footage (some LVP has it pre-attached — check first).

How much flooring do I need?

To figure out how much flooring you need, measure the room’s length × width for square footage, add a waste allowance for your install pattern — about 10% for straight rows, 15% for diagonal, or 20% for herringbone — then divide by the coverage printed on the box (around 20 sq ft for laminate, 22 for engineered hardwood, 24 for vinyl plank). For example, a 12 ft × 15 ft living room in straight-laid laminate is 180 sq ft; with 10% waste that’s 198 sq ft, so you’d buy 10 boxes at 20 sq ft each. It’s smart to grab one extra box as attic stock for future repairs. Enter your room above for an instant box count you can save or share.

How to use this calculator

Measure the room. Enter length × width in feet, or switch to Total area and type the square footage.
Pick the flooring. Choose laminate, engineered, vinyl plank or hardwood to set a typical box coverage.
Choose the layout. Select straight, diagonal or herringbone — the pattern sets the waste allowance.
Read your box count. See boxes to buy plus the spare attic-stock box, then save or share the estimate.

Tips & real-world notes

Buy one extra box and keep it sealed — dye/production lots change, so a repair box bought later rarely matches.
Coverage varies by product: always divide by the sq ft printed on your actual box, not a rule of thumb.
Diagonal and herringbone layouts create more off-cuts — bump waste to 15–20% so you don’t run short mid-install.
Floating laminate and LVP usually need underlayment sized to the same square footage (some LVP has it pre-attached).
Order all boxes in one purchase so they share a production lot and the shade matches across the floor.

Frequently asked questions

How many boxes of flooring do I need?

Find the room’s square footage (length × width), add your pattern’s waste (10% straight, 15% diagonal, 20% herringbone), then divide by the coverage on the box. A 12 × 15 room in straight laminate is 180 sq ft → 198 with waste → 10 boxes at 20 sq ft each.

How much extra flooring should I buy for waste?

Plan about 10% extra for standard straight rows, 15% for a diagonal layout, and up to 20% for herringbone or other complex patterns. The more angled cuts a pattern needs, the more off-cuts you throw away.

How much more does herringbone or diagonal flooring waste?

A diagonal install typically wastes about 15% versus 10% for straight rows, and herringbone runs closer to 20% because almost every plank is cut on an angle. Busy rooms with lots of jogs and closets can push it higher.

Do I need underlayment under laminate or vinyl plank?

Floating laminate almost always needs a foam or cork underlayment, and floating LVP usually does too — unless the plank has a pad pre-attached. Buy underlayment for the same square footage as the floor. Nail-down and glue-down floors generally don’t use a separate underlayment.

Laminate vs vinyl plank vs hardwood — how much does a box cover?

It varies by product, but a typical box covers about 20 sq ft for laminate, 22 sq ft for engineered hardwood, 24 sq ft for vinyl plank (LVP), and around 20 sq ft for solid hardwood. Always confirm with the coverage printed on the box you’re buying and override the calculator if it differs.

What is attic stock and how much should I keep?

Attic stock is spare flooring you set aside for future repairs. Keep at least one full sealed box: production lots and colors shift over time, so a plank bought years later rarely matches. This calculator recommends the spare separately so it doesn’t inflate your main box count.

How many boxes of laminate for a 12x15 room?

A 12 × 15 room is 180 sq ft. With 10% waste for a straight layout that’s 198 sq ft, and at 20 sq ft per box you’d buy 10 boxes — plus a spare box as attic stock, for 11 total.