Flooring Calculator
Work out exactly how many boxes of flooring to buy - for one room or the whole house. Add a room for every space (split L-shaped rooms into rectangles), and we total the area, waste, boxes and cost.
How it works
The math is simple and we show every step:
- Room area = length x width
- Total area = all rooms added together
- Area to cover = total area x (1 + waste %)
- Boxes to buy = area to cover / coverage per box, rounded UP to the next whole box
- Estimated cost = boxes x price per box
Worked example
A bedroom is 12 ft x 10 ft = 120 sq ft. With 10% waste that is 132 sq ft to cover. At 20 sq ft per box, 132 / 20 = 6.6, so you buy 7 boxes. At $55 a box the flooring costs about $385, and the 7 boxes cover 140 sq ft, leaving a little spare for repairs.
Assumptions to know
- Waste defaults to 10% - raise it for diagonal or patterned layouts.
- Coverage per box comes from the box label; it varies a lot between products.
- Underlayment, trim and transition pieces are not included in the box count.
Results are planning estimates only. Always check the coverage and instructions on the actual product you buy, and measure your own space carefully before ordering. When in doubt, a little extra material is cheaper than a second trip or a stalled job.
Frequently asked questions
How much extra flooring should I buy for waste?
10 percent is the common starting point for a straight layout in a rectangular room. Use 15 percent for diagonal or herringbone layouts, rooms with lots of cuts, or if you are new to installing flooring.
How do I measure an L-shaped room?
Split it into two rectangles, add each rectangle as its own room or section above, and the calculator adds the areas together for you.
Why round up to whole boxes?
Flooring is sold in sealed boxes, so you always buy the next whole box above the area you need. Keep the leftover planks or tiles - they are perfect for future repairs.
Does this work for laminate, vinyl plank, hardwood and tile?
Yes. Any flooring sold by the box works the same way: room area, plus waste, divided by the coverage printed on the box.