Flooring Calculator
This flooring calculator works out how many boxes of laminate, vinyl plank or hardwood flooring to buy for a room. It uses the room size and the coverage printed on the box, and adds waste for a straight, diagonal or herringbone layout.
Result
10 boxes of flooring
| Room area | 180 ft² |
|---|---|
| Needed incl. 10% waste | 198 ft² |
| Area in full boxes | 200 ft² |
| Left over | 2 ft² |
Results update as you type.
How Much Flooring Do I Need?
Flooring is sold by the box, and every box lists how many square feet it covers. So the estimate is simple: measure the room, add waste for cuts, and divide by the coverage per box. The tricky part is choosing the right waste allowance, which is why the calculator sets it for you from the layout you pick.
How to Calculate Flooring by Hand
1. Room area
Area (ft²) = length (ft) × width (ft)
2. Add waste
Needed (ft²) = area × (1 + waste ÷ 100)
Use about 10% for straight lay, 15% for diagonal and 15% or more for herringbone.
3. Boxes
Boxes = needed ÷ coverage per box, rounded up
Worked example: an L-shaped living room
The main part of the room is 15 × 20 feet, with an 8 × 10 foot dining nook off one end. You’re laying vinyl plank straight, and each box covers 20 ft²:
- Main area: 15 × 20 = 300 ft²
- Nook: 8 × 10 = 80 ft²
- Total: 380 ft²
- With 10% waste: 380 × 1.10 = 418 ft²
- Boxes: 418 ÷ 20 = 20.9, rounded up to 21 boxes (420 ft²)
To use the calculator for an L-shaped room, enter the total area as the length (380) and 1 as the width.
Tips & Common Mistakes
Read the carton, not the website listing
Coverage per box varies widely, even within one product line, because plank widths and lengths differ. Use the number printed on the box you’re actually buying. A wrong coverage figure is the most common reason people come up short.
Acclimate before you install
Many laminate, engineered and solid wood floors need to sit in the room for a period before installation so the boards adjust to the temperature and humidity. Follow the manufacturer’s instructions. Skipping this step can lead to gaps or buckling and may void the warranty.
Underlayment matches the room area, not the flooring
Underlayment rolls cover the floor once with no pattern waste. Buy it for the room area (380 ft² in the example above), not the area including waste. Some vinyl and laminate products have underlayment attached, so check before buying extra.
Mix boxes as you go
Shade and grain vary from box to box. Open three or four boxes at a time and pull planks from each so no patch of the floor ends up noticeably lighter or darker.
Plan the transitions
Where the new floor meets tile, carpet or a different height, you’ll need transition strips. Count the doorways and openings while you’re measuring. For tiled areas such as bathrooms, use our tile calculator.
Frequently Asked Questions
How much extra flooring should I buy?
Plan on about 10% extra for a straight layout and about 15% for diagonal or herringbone patterns, which create more angled cuts. Rooms with lots of corners, closets or doorways need more than an open rectangle. Keep an unopened box for future repairs.
How many boxes of flooring do I need for 500 square feet?
With 10% waste you need 550 square feet. With boxes that cover 20 square feet each, that is 27.5, so 28 boxes. With boxes that cover 23.4 square feet, it is 23.5, so 24 boxes. Always check the coverage printed on your carton.
How do I measure a room for flooring?
Measure the length and width at the widest points and multiply them. Include closets and alcoves that get the same floor. For L-shaped or irregular rooms, split the space into rectangles and add their areas, then enter the total.
Should flooring run the same direction through doorways and hallways?
Usually, yes. Running the floor continuously through connected rooms looks seamless and avoids extra transitions. Include those connected areas in your total so the waste allowance covers them.
Can I return extra boxes of flooring?
Many retailers accept unopened boxes within their return window, but policies vary, especially for special-order products. Check before you buy. Rounding up to a full box usually leaves you a few spare planks for future repairs anyway.
Why does herringbone flooring need more waste?
In a herringbone pattern every plank meets the wall at an angle, so the perimeter takes many angled cuts. Offcuts are also harder to reuse than in a straight layout. Use at least 15% waste, and more for small rooms.
Related Calculators
- Tile CalculatorTiles and boxes for floors, walls and backsplashes, with waste.
- Paint CalculatorGallons and quarts of paint and primer for walls and ceilings.
- Drywall CalculatorSheets of 4×8, 4×10 or 4×12 drywall for walls and ceilings.
- Deck CalculatorDeck boards, linear feet and joists for a rectangular deck.
Sources & Assumptions
- Boxes = room area × (1 + waste) ÷ coverage per box, rounded up to whole boxes.
- Waste of 5–10% for straight layouts and 10–15% for diagonal or herringbone is common installer guidance. Defaults are the upper end of each range.
- Coverage per box comes from the product carton. Follow the manufacturer's installation instructions for acclimation and expansion gaps.
- Areas are rounded only for display. Box counts always round up.
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