Flooring calculator
Enter the room size, a waste allowance and the coverage per box to see the square feet to order, the boxes to buy and the cost.
Buy this many boxes
10
184.80 sq ft including waste, for a 168.00 sq ft floor
How to use it
- Measure the room at its longest and widest points, in feet. For an L-shaped room, measure it as two rectangles and add the second with the rooms field or a second calculation.
- Set the waste allowance. 10% is right for a straight layout in a simple room; go to 15% for diagonal or patterned layouts and 20% for rooms with lots of angles and closets.
- Enter the square feet per box from the packaging, and the price per square foot if you want the cost.
- Read the boxes to buy. Order them all from one lot so the colour matches, and keep a spare box.
Worked example
A 14 ft by 12 ft bedroom, laminate in 20 sq ft boxes at $2.49 a square foot, with 10% waste.
Floor area 168 sq ft. With waste: 168 × 1.10 = 184.8 sq ft. Boxes: 184.8 ÷ 20 = 9.24, so 10 boxes, which is 200 sq ft and leaves 32 sq ft spare. Cost: 200 × $2.49 = $498.00.
The same room laid diagonally at 15% waste needs 193.2 sq ft, which is still 10 boxes.
How this is calculated
The floor area is length times width in feet, times the number of rooms of that size. Flooring is always bought with extra for the cuts at walls and around obstacles, for damaged pieces, and for the boards you'll want to keep for repairs, so the area is increased by the waste percentage before ordering. Boxes are counted by dividing the area including waste by the coverage printed on the box and rounding up, since stores sell whole boxes. The leftover line shows how much you'll have beyond the floor itself. Cost is the material only, at the price per square foot times the square feet in the boxes you actually buy, not the floor area.
floor area = length × width × rooms
square feet to buy = floor area × (1 + waste %)
boxes = square feet to buy ÷ coverage per box, rounded up
cost = boxes × coverage per box × price per square foot
Rates, sources and limits
Last reviewed 23 Sep 2026 by the CalcRabbit team. Estimates only, not financial, tax or medical advice.
Frequently asked questions
How much waste should I allow?
10% covers cuts in a rectangular room with planks laid parallel to a wall. Diagonal and herringbone patterns waste more at every edge, so 15%. Rooms with closets, bays and many corners, or tile with a pattern to match, run 15% to 20%. It's cheaper to have a box left over than to find the lot has changed when you need one more.
Is the price per square foot the price per box?
No. Boxes are priced by their coverage: a $49.80 box of 20 sq ft is $2.49 a square foot. Compare products per square foot, then buy whole boxes. The calculator charges for the boxes you buy, not the floor area.
Do I count closets and under the cabinets?
Count closets if you're flooring them, which you usually are. Kitchen cabinets and islands are normally not floored underneath for laminate and vinyl, but are for tile that goes down before the cabinets. Measure accordingly.
What about underlayment and trim?
Underlayment is sold by the roll in square feet and needs the floor area without waste, plus a little for overlap. Transition strips and quarter-round are by the linear foot; measure the room's perimeter minus doorways for the trim.