Flooring Calculator
Find how many boxes of laminate, vinyl plank or hardwood flooring to buy for your square footage, with the right extra for cuts and your layout.
Flooring comes by the box, and every row ends in a cut, so you need more than the floor's square footage. A straight layout wastes about a tenth; laying the planks diagonally or in herringbone takes more angled cuts and more extra.
Square feet of floor
The area you're covering, less anything you're skipping. For one room, multiply length by width: a 10 × 12 room is 120 sq ft.
Coverage per box
Printed on the box or the product page, in square feet.
How the planks run
Angled layouts waste more at the walls.
Boxes to buy
66 boxes
1,200 sq ft of floor plus 10% for cuts
Buy every box from the same production lot, printed on the box, so the color matches. Small rooms with closets and doorways can take a little more.
💡About this calculator▼
Plank flooring is sold by the box, and every box covers a set number of square feet. The catch is that you can't buy exactly your floor's square footage: every row ends in a cut, and angled layouts throw away more.
This works out the boxes. Enter the square feet of floor you're covering, the square feet one box covers, and how the planks will run. You get the boxes to buy and the square footage they cover, with the right extra for cuts already added.
It works for any plank floor: laminate, luxury vinyl plank, and engineered or solid hardwood. For tile, use our tile and grout calculator.
Floor area. The square feet you're covering: the whole floor's area less anything you're skipping, like tiled bathrooms, or for a single room its length times its width.
Extra for cuts. Flooring makers and installers add about 10 percent for a straight layout, where planks run the length of the room. Diagonal and herringbone layouts need more angled cuts at the walls, so they take about 15 percent.
Boxes. The floor area plus that extra, divided by the square feet one box covers, rounded up to a whole box.
Worked example. A 16-by-20-foot room is 320 square feet. Laid straight, add 10 percent for 352 square feet. With boxes that cover 20 square feet each, that's 17.6, so buy 18 boxes, 360 square feet of flooring. Laid diagonally, add 15 percent instead: 368 square feet, 19 boxes.
📐How it's calculated▼
Floor area = the square feet you're covering (for one room, length × width).
Flooring with extra = floor area × 1.10 (straight) or × 1.15 (diagonal or herringbone).
Boxes = flooring with extra ÷ square feet per box, rounded up.
16 × 20 ft room, 20 sq ft boxes, straight: 320 sq ft → 352 → 18 boxes. 10 × 12 ft room: 120 sq ft → 132 → 7 boxes. 1,200 sq ft of floor: 1,320 sq ft with extra → 66 boxes.
📎Sources:Diamond W — Engineered hardwood installation instructions (cutting allowance, diagonal waste),Havwoods — Flooring wastage allowances by layout
🔍Finding your inputs▼
Square feet of floor: The area you're covering. For a whole floor of the house, start from the home's square footage and subtract anything you're not redoing, like tiled bathrooms or the kitchen. For a single room, multiply its length by its width; a 10-by-12-foot room is 120 square feet.
Coverage per box: The square feet one box covers, printed on the box and on the product page. It varies a lot by product, so check yours.
How the planks run: Straight means rows parallel to a wall. Choose diagonal or herringbone if the planks run at an angle or in a zigzag pattern, which takes more cuts.
⚠️Special situations▼
My room is L-shaped or odd
Split it into rectangles, multiply each one’s length by its width, and add them up. Or start from the home’s total square footage and subtract the areas you’re not covering.
I’m doing a whole floor of the house
Start from the house’s square footage and subtract the rooms you’re not redoing, like tiled bathrooms or the kitchen. On a large open floor the standard extra is generous; on lots of small rooms and hallways it can run tight.
Should I keep extra flooring?
A spare box is worth keeping for future repairs, since colors and styles get discontinued. If the boxes come out exactly even, buying one more covers a damaged plank or a mistake.
❓Common questions▼
How many boxes of flooring do I need?
Multiply the room’s length by its width, add 10 percent for cuts, and divide by the square feet per box, rounding up. A 16-by-20-foot room with 20-square-foot boxes takes 18 boxes.
How much flooring do I need for a 10x12 room?
A 10-by-12-foot room is 120 square feet; with 10 percent extra for cuts, buy about 132 square feet. With boxes that cover 20 square feet, that is 7 boxes.
What waste factor should I use for flooring?
About 10 percent for a straight layout and about 15 percent for diagonal or herringbone. Small rooms with many corners can use a little more, and very large open rooms a little less.
How do I measure a room for flooring?
Measure the length and width wall to wall at the widest points, in feet, and multiply. Split L-shaped or irregular rooms into rectangles, and include closets with the room they open into.
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