Flooring Calculator: How Many Boxes Do I Need?

Estimate only. Check product labels and local building rules before you buy or build.

Quick answer

Multiply each room’s length by its width, add the rooms together, add 10% for cutting waste (15% for a diagonal layout), then divide by the square feet in one box and round up. A 12 × 14 ft room is 168 sq ft, or 184.8 sq ft with 10% waste, which is 9 boxes of 21.24 sq ft.

How to use the flooring calculator

Measure each room wall to wall at floor level and enter its length and width. Add a room for every space that gets the same flooring, or switch to Total area if you already know the square footage.
Choose the flooring type and the layout. The layout sets the cutting waste: 10% for straight rows, 15% for diagonal and herringbone. You can change the percentage under Waste, doorway width and product sizes.
Type the square feet per box printed on your carton. The number of boxes updates as you type and is always rounded up to whole boxes.
Under Baseboard and underlayment, enter the number of doorways to get the baseboard length and pieces, and choose whether you need underlayment rolls.

How do you calculate how much flooring you need?

Add up the floor area, add a cutting allowance, divide by the area one box covers and round up. Flooring is sold in whole boxes, and each carton states how many square feet it covers. The allowance pays for the offcuts at the ends of rows and along the walls that are too short to reuse.

Baseboard follows the walls instead of the floor: add up the room perimeters, subtract the width of each doorway, and divide by the length of one piece. Underlayment covers the floor area itself, so it gets no waste allowance and is rounded up to whole rolls.

floor area = length × width, added up over the roomsarea with waste = floor area × (1 + waste % ÷ 100)boxes = area with waste ÷ sq ft per box, rounded upbaseboard length = room perimeters − doorways × doorway widthbaseboard pieces = baseboard length ÷ piece length, rounded upunderlayment rolls = floor area ÷ sq ft per roll, rounded up

How many boxes of flooring do I need for my room?

A 12 × 12 ft room needs 8 boxes of 21.24 sq ft with 10% waste, or 6 boxes of 31.16 sq ft. The table works out other common room sizes the same way: length × width, plus 10%, divided by the box size and rounded up. The two box sizes are a laminate carton and an engineered hardwood carton from the makers’ product pages.

Boxes of flooring by room size, straight layout with 10% cutting waste (box sizes in sq ft)
Room (ft)	With waste (sq ft)	Boxes of 21.24	Boxes of 31.16
10×10	110	6	4
10×12	132	7	5
12×12	158.4	8	6
12×14	184.8	9	6
12×16	211.2	10	7
14×16	246.4	12	8
15×20	330	16	11
20×20	440	21	15

For a diagonal or herringbone layout, use 15% waste in the calculator instead.

Worked examples

Laminate in a 12 × 14 ft bedroom

The bedroom is 14 ft by 12 ft, so the floor is 14 × 12 = 168 sq ft. Laid in straight rows, it gets 10% waste: 168 × 1.10 = 184.8 sq ft. The laminate comes in cartons of 21.24 sq ft, and 184.8 ÷ 21.24 = 8.70, so buy 9 boxes. Together they cover 191.16 sq ft.

The perimeter is 2 × (14 + 12) = 52 ft. Taking off one 3 ft doorway leaves 49 ft of baseboard, which is 7 pieces of 8 ft. Underlayment in 100 sq ft rolls takes 168 ÷ 100 = 1.68, so 2 rolls.

Engineered hardwood laid diagonally in two bedrooms

Bedroom one is 12 × 11 ft (132 sq ft) and bedroom two is 10 × 10 ft (100 sq ft), 232 sq ft in total. A diagonal layout starts at 15% waste: 232 × 1.15 = 266.8 sq ft. With 22.6 sq ft per box, 266.8 ÷ 22.6 = 11.81, so buy 12 boxes, which cover 271.2 sq ft.

The two perimeters are 46 ft and 40 ft, 86 ft together. Two 3 ft doorways leave 80 ft of baseboard, exactly 10 pieces of 8 ft. If the planks have no pad attached, 232 sq ft of underlayment takes 3 rolls of 100 sq ft.

How much extra flooring should I buy?

Buy 10% more than the floor area for straight rows and 15% more for a diagonal layout. A laminate maker tells buyers to add 10% to the square footage for cuts and waste, and 20% for a tile pattern. A hardwood maker suggests 5% for a straight install and 10% to 15% for a diagonal one, because every board along the walls is cut at an angle.

One wood flooring supplier gives 15% for herringbone and chevron floors in areas under 100 m² (about 1,076 sq ft) and 12% above that, so the calculator starts herringbone at 15%, the same as diagonal. If your product’s installation instructions give a number, type that into Cutting waste instead. Raise the percentage for rooms with many corners, closets or a hearth to cut around.

How many square feet are in a box of flooring?

The boxes we checked hold 21.24 to 31.16 sq ft, and the figure changes with plank width and thickness. These are the products the calculator starts with, taken from the manufacturers’ own product pages.

Coverage per box, roll or piece of flooring products sold in the US
Flooring	Product checked	Coverage
Laminate	7.55 in wide plank	21.24 sq ft per box
Vinyl plank	9 × 59 in plank, 6.5 mm thick	21.79 sq ft per box
Engineered hardwood	5 in hickory, 7/16 in thick	22.6 sq ft per box
Engineered hardwood	9.25 in oak, 1/2 in thick	31.16 sq ft per box
Solid hardwood	3-1/4 in oak, 3/4 in thick	22 sq ft per box
Foam underlayment	3 × 33.3 ft roll	100 sq ft per roll
MDF baseboard	5/8 × 5-1/2 in profile	8 ft per piece

Always use the coverage printed on your own carton or roll.

Questions

How many boxes of flooring do I need for a 12×12 room?

A 12 × 12 ft room needs 8 boxes of 21.24 sq ft flooring. The floor is 144 sq ft, and with 10% cutting waste you need 158.4 sq ft. Dividing 158.4 by 21.24 gives 7.46, which rounds up to 8 boxes covering 169.92 sq ft. With larger 31.16 sq ft boxes, 6 boxes are enough.

How much baseboard do I need for a room?

You need the room perimeter minus the doorways. A 12 × 14 ft room has a perimeter of 52 ft, and one 3 ft doorway leaves 49 ft, which is 7 pieces of 8 ft baseboard. The count assumes you join pieces along a wall. Each outside corner is cut at an angle, so buy one more piece if the room has several corners.

Do I need underlayment under laminate or vinyl plank?

You need underlayment under a floating floor unless the planks already have a pad attached. One maker’s page for a floating engineered hardwood says that if the flooring does not have attached padding, an underlayment pad must be rolled out over the subfloor. The vinyl plank the calculator starts with lists an EVA pad, so choosing vinyl plank switches underlayment off. Foam underlayment comes in rolls such as 100 sq ft (3 × 33.3 ft), and one maker sells a separate underlayment for vinyl plank.

Should I buy extra boxes for future repairs?

Yes, one or two spare boxes are worth keeping. A hardwood flooring maker recommends buying one or two cartons beyond the calculated amount, so that boards damaged later, for example by a water leak, can be replaced with matching ones. The calculator does not add these spares, so add them to the box count yourself.

How do I measure an L-shaped room for flooring?

Split the L into two rectangles, measure each one and enter them as two rooms. A 15 × 12 ft area with an 8 × 6 ft alcove is 180 + 48 = 228 sq ft. Do not use the two perimeters for baseboard, because the line between the rectangles is not a wall: measure the real walls and type their total into Wall length for baseboard.

Sources

Swiss Krono USA, How to measure for laminate flooring (checked October 19, 2026)Add 10% to the square footage for cuts and waste, 20% for a tile pattern.
Mullican Flooring, How to Calculate the Correct Footage When Purchasing Hardwood Flooring (PDF) (checked October 19, 2026)About 5% extra for a straight install, 10% to 15% for diagonal, and 1 to 2 spare cartons for repairs.
Shaw Floors, Oak Grove laminate, Pampas Grass (SL119-01049) (checked October 19, 2026)21.24 sq ft per carton, 7.55 in wide.
Shaw Floors, Fresh Take vinyl plank, Tuxedo Bronze (3415V-00935) (checked October 19, 2026)21.79 sq ft per carton, 9 × 59 in planks, 6.5 mm thick, EVA pad listed.
Shaw Floors, Landmark Sliced Oak engineered hardwood, Glacier (SW747-01118) (checked October 19, 2026)31.16 sq ft per carton, 9.25 in wide, 1/2 in thick.
Bruce, Hydropel Natural 5" Hickory Engineered Hardwood (EHWR54L10WR) (checked October 19, 2026)22.6 sq ft per box, 7/16 in thick, locking joints for floating or gluing; an underlayment pad is rolled out first if the flooring has no attached padding.
Bruce, Dundee Timeless Appeal 3-1/4" Oak Solid Hardwood (CB3250LG) (checked October 19, 2026)22 sq ft per box, 3/4 in thick, nailed down.
MP Global Products, QuietWalk underlayment (checked October 19, 2026)100 sq ft rolls (3 × 33.3 ft) for laminate and floating wood; a separate product is sold for vinyl plank.
Alexandria Moulding, Primed MDF Step Baseboard (03533) (checked October 19, 2026)5/8 × 5-1/2 in profile in 96 in (8 ft) lengths.
Havwoods, Everything you need to know about wastage (checked October 19, 2026)15% wastage allowance for herringbone and chevron in areas under 100 m², 12% above; 10% and 7% for plank flooring.

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