Flooring Calculator
Calculate how much flooring you need for a room, including waste, with the number of boxes to buy and an optional cost estimate
Last updated: November 4, 2026
How to Use the Flooring Calculator
How to calculate how much flooring you need
- Measure the room. Use a tape measure to find the length and width of the floor. Measure at the widest points and include closets that will get flooring.
- Enter the size. Choose feet or meters and type the length and width.
- Pick the layout. The layout sets a suggested waste allowance. Choose straight, diagonal or pattern, or type your own percentage.
- Add the box coverage. Enter the square feet per box printed on the carton to see how many boxes to buy. Leave it empty if you only want the total area.
- Add extras (optional). Open Advanced options to include a second area, subtract fixed cabinets or add a price per square foot for a cost estimate.
Round up to full boxes, and buy everything from the same production lot so color and texture match. Always confirm the final quantity with your installer or the manufacturer's guide before you order.
Formula & Methodology
Flooring formula
Flooring to buy = Floor area × (1 + Waste %)
If your flooring is sold in boxes:
Boxes = Flooring to buy ÷ Coverage per box, rounded up to a whole box.
The floor area of a rectangular room is length × width. For an L-shaped room or a room with a hallway, split it into rectangles, work out each area, and add them together. Subtract any area that will not get flooring, such as a kitchen island.
Worked example
A living room is 15 ft × 12 ft. You are installing straight-lay laminate with 10% waste, and each box covers 20 sq ft.
- Floor area = 15 × 12 = 180 sq ft
- With waste = 180 × 1.10 = 198 sq ft
- Boxes = 198 ÷ 20 = 9.9, so buy 10 boxes (200 sq ft)
- Extra from rounding up = 200 − 198 = 2 sq ft, on top of the 18 sq ft you allowed for waste. Spare planks are useful for future repairs.
At $3.50 per square foot, the material cost is 200 × $3.50 = $700.
How much extra flooring should you buy?
- 5%: simple rooms with vinyl plank or carpet tile
- 10%: the standard allowance for straight-lay laminate, hardwood, engineered wood and tile
- 15%: diagonal layouts, which create more angled cuts
- 20%: herringbone, chevron and other patterns, and rooms with many corners
Cuts at the walls, planks that arrive damaged and mistakes all use up material, and a few extra planks from the same batch are valuable if a board needs replacing years later.
Square meters
In metric the formula is the same. Measure in meters, which gives square meters (m²), and use the box coverage in m². One square meter is about 10.76 square feet.
About Flooring Calculator
Our flooring calculator is a free, easy-to-use tool designed to help youcalculate how much flooring you need for a room, including waste, with the number of boxes to buy and an optional cost estimate. For professionals or those who need quick calculations, our calculator provides accurate results instantly.
Frequently Asked Questions
How much flooring do I need?
Multiply the room length by the width to get the area, then add 5% to 20% for waste. A 15 ft by 12 ft room is 180 sq ft, so you need about 198 sq ft with a typical 10% allowance.
How much extra flooring should I buy for waste?
Ten percent is standard for straight-lay laminate, hardwood and tile. Use about 5% for simple vinyl plank rooms, 15% for diagonal layouts, and 15 to 20% for herringbone or patterned floors or rooms with many corners and cuts.
How many boxes of flooring do I need?
Divide the area you need to buy (including waste) by the square feet in one box, then round up to a whole box. For 198 sq ft and 20 sq ft boxes, you need 10 boxes.
How do I calculate flooring for an L-shaped room?
Split the room into two rectangles, multiply the length by the width for each one, and add the areas. In this calculator, use the second area fields under Advanced options.
Should I include closets, doorways and hallways?
Yes, include any space that will get flooring, including closets and hallways. Do not include space under fixed cabinets or a kitchen island. Use the subtract field for those areas.
How do I calculate laminate or vinyl plank flooring?
The method is the same for laminate, vinyl plank, hardwood and engineered wood: find the floor area, add the waste allowance, and divide by the box coverage. Planks are cut to fit at the walls, so the waste allowance matters more than the plank size.
How do I convert square feet to square meters for flooring?
Multiply square feet by 0.0929 to get square meters, or switch the calculator to meters. One square meter is about 10.76 square feet. For example, a 180 sq ft room is about 16.7 m².
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