Flooring Calculator
How many boxes, square feet, or square yards of flooring you need — laminate, vinyl plank, hardwood, or carpet. Free, browser-only, no signup.
1. Rooms & areas
2. Material
3. Layout pattern (waste factor)
How the flooring calculator works
Flooring estimates come down to three steps: measure the net floor area, add a waste factor for the cuts your layout will produce, and convert the result into the units stores actually sell — whole boxes for plank flooring, or a length cut from a roll for carpet. Most online calculators stop at "area × waste". This one finishes the job: it rounds plank orders up to whole boxes from your product's real per-box coverage, and it computes carpet from roll widths the way a carpet shop would.
Measure each room at its widest points, and round up to the nearest inch. If a room is L-shaped, split it into two rectangles and enter both as separate rows. The same goes for closets and hallways — if the new floor runs into them, they count, and they are the single most commonly forgotten part of a flooring measurement.
How much extra flooring to buy (the waste factor)
Every install produces offcuts — planks trimmed at walls, pieces that end up too short to reuse, boards sacrificed to stagger seams. Manufacturer installation guides quantify this as a percentage on top of the measured area:
| Layout | Waste to add | What the sources say |
|---|---|---|
| Straight / standard | 10% | Pergo and Swiss Krono consumer guides say 10%; the NWFA professional minimum is a 5% cutting allowance |
| Diagonal (45°) | 15% | Pergo's install guide says 15% for diagonal installs (Bruce allows 10%) |
| Herringbone / chevron | 15–20% | Retailer guidance runs 10–15%; Swiss Krono says add 20% for patterned layouts. This calculator uses 18% |
| Complex rooms | +5 points | Guides recommend roughly 8–15% total for rooms with many angles, closets, and doorways |
If you have leftover material at the end, that is the system working. Color varies slightly between production runs — the industry calls these dye lots — so a plank bought two years from now may not match the floor you have. Keep at least one unopened box for future repairs.
Why you buy boxes, not square feet
Plank flooring is shelved and sold by the carton, and coverage per carton varies more than most people expect. Across current product lines, laminate runs roughly 16–27 sq ft per box, vinyl plank 19–37, engineered hardwood 26–37, and solid hardwood around 22. Two consequences follow. First, always round up to a whole box — 10.2 boxes means 11 boxes. Second, the per-box coverage changes your real cost: a price that looks lower per square foot can total higher at checkout once you round up. That is why this calculator prices the order from boxes purchased, not raw area.
How carpet is different: square yards and 12-foot rolls
Carpet is not boxed — it is manufactured on rolls, most commonly 12 feet wide (13 ft 6 in and 15 ft widths also exist), and trade pricing is often quoted per square yard, which is 9 square feet. You buy a length cut from the roll, which has a consequence the simple area formula misses: a 10 ft-wide room still consumes the full 12 ft roll width, and a 14 ft-wide room needs two strips with a seam between them.
This calculator runs that strip math for each room: it tries both orientations, picks the one that wastes less, adds a 3-inch trim allowance per cut, and flags any room that needs a seam. Seam placement and pile direction matter — strips must run the same way, and patterned carpet needs extra material to match the repeat — so treat a seam flag as a sign to confirm the cut plan with your installer. Carpet also sits on a separate pad (cushion), which the calculator reports as its own line; replacing the pad along with the carpet is standard practice and some warranties require it.
Underlayment and stairs
Floating floors (laminate and many vinyl planks) need a thin underlayment layer unless the plank has a pad already attached — in that case, skip it; manufacturers warn against doubling up. Underlayment is sold in rolls, commonly 100 sq ft each, and the calculator divides your net floor area by the roll coverage and rounds up.
For stairs, the calculator estimates each step as your step width × (10 in tread + 7¾ in riser), the standard residential stair dimensions under the International Residential Code. Hard flooring on stairs also needs stair nosing for each step edge — that is sold separately per linear foot and is not included here.
Privacy
Everything runs in your browser. Room dimensions, material choices, and cost estimates are never sent to any server. Inputs save only to local browser storage so the form remembers your last entry. Open developer tools and check the Network tab — nothing leaves your machine while you use this calculator.
Source notes
Waste factors per manufacturer installation documentation: NWFA guidelines (5% minimum cutting allowance), Pergo Installation Essentials Guide (10% standard, 15% diagonal), Swiss Krono (10% standard, 20% patterned), and Bruce/AHF install instructions. Carpet roll widths and 5–10% seam allowance per Flooring America. Box coverage ranges compiled from current Pergo, COREtec, SMARTCORE, and Bruce product listings. Stair dimensions per IRC residential limits (10 in tread, 7¾ in max riser). Estimates are planning figures — actual usage varies by jobsite, installer, and product; confirm quantities with your retailer before ordering.