Flooring Calculator
Convert room dimensions into boxes of flooring, using the coverage printed on the box and a waste allowance for cuts.
Estimates are for planning. Confirm quantities against your measured site and product packaging before ordering, and follow local building codes.
How to measure the room
Measure the room at its longest and widest points, wall to wall, in feet. Multiply the two for the square footage of a rectangular room. A 12 × 15 ft bedroom is 180 sq ft.
Real rooms are rarely clean rectangles. For an L-shape, split it into two rectangles, calculate each, and add them. Do the same for hallways, closets, and pantry floors if the new flooring runs into them; closets are the most commonly forgotten area and they add up fast. Measure into doorways to the point where the new floor will meet the old one, usually the centerline under the closed door.
If the flooring will run continuously through several rooms, measure each room and hallway separately and total them rather than trying to capture the whole footprint in one shot. Write the numbers down as you go. Re-measuring once is cheaper than a second delivery fee.
Don’t subtract for kitchen islands or vanities unless they’re enormous. The cuts around fixed objects generate waste that roughly cancels out the area you’d save.
The formula and what it assumes
The calculator does this:
Boxes = room area × (1 + waste %) ÷ coverage per box, rounded up to the next whole box.
So a 180 sq ft room with 10% waste needs 198 sq ft of material. If your carton covers 22.5 sq ft, that’s 198 ÷ 22.5 = 8.8, which rounds up to 9 boxes. The round-up is non-negotiable: stores sell full cartons, not loose planks.
The default waste factor is 10%, which covers end-of-row cuts, the occasional miscut, and planks with defects or grain you don’t like. Use 15% when you’re installing on a diagonal, doing herringbone or another pattern, or working in a room with many angles, alcoves, and jogs, because angled cuts leave triangular offcuts that can’t start the next row.
The formula assumes you’ll enter the coverage printed on the actual carton. That number is the one assumption you control completely, and it varies a lot: two laminate products on the same shelf can differ by 5 sq ft per box. It also assumes reasonably efficient cutting, meaning you start new rows with the offcut from the previous row when stagger rules allow it.
Buying tips
US flooring cartons don’t have a standard size, but typical ranges hold: laminate runs about 18-25 sq ft per box, luxury vinyl plank (LVP) about 19-28 sq ft, engineered hardwood about 17-31 sq ft, and solid hardwood around 20-22 sq ft. The exact figure is printed on the end of every carton and listed on the product page at Home Depot, Lowe’s, and Floor & Decor.
When comparing products, look past the photo. For laminate, the AC rating tells you durability: AC3 handles normal residential traffic, AC4 takes heavy residential and light commercial use. For LVP, the wear layer thickness is the equivalent spec: 12 mil suits bedrooms and low-traffic areas, while 20 mil or thicker stands up to kids, dogs, and kitchens. Thicker wear layers cost more and earn it in high-traffic rooms.
Buy all your boxes at once and check that the lot or batch numbers on the cartons match, since color can shift slightly between production runs. Bring the cartons into the room and let them acclimate for the period the manufacturer specifies, usually 48 to 72 hours for wood and laminate, before you open them.
Order one box beyond what the calculator says if you’re within a plank or two of the boundary. Major retailers take back unopened cartons, typically within 90 days with a receipt, so the cost of overbuying is a return trip, while the cost of underbuying is a stalled install and a possible lot mismatch. And once the job’s done, stash one full box in the basement. Future you, staring at a gouged plank in front of the fridge, will need it.
Frequently asked questions
How much extra flooring should I order for waste?
10% extra is the standard for a straight-lay install in a roughly rectangular room. Go to 15% for diagonal layouts, herringbone patterns, or rooms with lots of angles, closets, and bump-outs, since every angled cut produces offcuts you can't reuse.
How many square feet are in a box of flooring?
It varies by product, which is why our calculator asks for the number printed on your carton. Laminate cartons commonly hold 18-25 sq ft, luxury vinyl plank around 19-28 sq ft, and solid hardwood about 20-22 sq ft. Always use the exact figure on the box you're buying.
Why does flooring need to acclimate before installation?
Wood and laminate expand and contract with temperature and humidity. Letting cartons sit in the room for the manufacturer-specified period, typically 48-72 hours, lets the planks adjust so they don't gap or buckle after installation. Check your product's instructions; some vinyl products skip this.
Should I keep leftover flooring?
Keep at least one full box. Dye lots and production runs change, so a plank bought two years later may not match. A spare box lets you replace a damaged plank with a perfect match, and click-lock floors make single-plank swaps realistic.