Flooring calculator
Enter every room by length and width — or type the square feet if you already have them — choose a waste allowance, and enter the coverage printed on the box. This adds up the floor, adds the waste, and tells you how many boxes to order, with the working shown. Then Add to an estimate puts the flooring on a free estimate as a line you can price and send.
The working: 120 + 80 = 200 sq ft. × 1.1 = 220 sq ft. ÷ 20 sq ft per box = 11, rounded up to 11 boxes.
How the flooring math works
Each room is length × width in square feet. Add the rooms together, multiply by one plus the waste percentage, and divide by the square feet in one box. Then round up, because boxes are not sold open.
A 12 × 10 ft kitchen is 120 sq ft and a 10 × 8 ft hall is 80 sq ft, so the floor is 200 sq ft. With 10% waste you are buying for 220 sq ft. If the carton says 20 sq ft per box, 220 ÷ 20 = 11 boxes. If it says 23.4, it is 9.4 — so 10 boxes, which actually delivers 234 sq ft. The calculator shows what arrives as well as what you need, so the difference is not a surprise.
How to measure for flooring
- Measure each room wall to wall at its longest and widest points, in feet. Round up to the next half foot; a quarter inch short at the far wall is a strip you cannot buy.
- Break L-shaped rooms into two rectangles and enter each as its own room.
- Include closets, the floor inside doorways, and any hallway that will carry the same floor through.
- Measure in the same units throughout. If you have measurements in inches, divide the area in square inches by 144 to get square feet.
Choosing a waste allowance
Waste is the material lost to cuts at walls and doorways, pieces with defects, and the pattern itself. It depends far more on the layout and the room than on the material. These are typical ranges installers start from; the product’s own installation guide may recommend something different.
| Layout | Typical waste |
|---|---|
| One large room, planks laid straight | 5–7% |
| Typical rooms, straight lay | 10% |
| Many small rooms, closets, angled walls | 12–15% |
| Diagonal layout | 15% |
| Herringbone or chevron | 15–20% or more |
Large-format tile and patterned or directional flooring often need more, because a cut piece cannot be turned around and used elsewhere.
Ordering tips
- Read the carton, not the website. Coverage per box differs between products in the same range, and the number printed on the box is the one that counts.
- Buy from one lot. Tile and wood vary in shade between production runs. Check that every box carries the same lot or run number.
- Acclimate if the maker says to. Many wood and laminate products ask for the boxes to sit in the room before installation; follow the instructions for the one you are using.
- Underlayment and trim are separate. Underlayment is usually the same square footage as the floor; transitions, stair nosing and baseboard or quarter round are counted by the linear foot.
Putting the flooring on an estimate
Add to an estimate opens the estimate generator with the flooring as a line: the product, the number of boxes, the square feet that delivers, the rooms it covers and the waste allowance. Give a price per box above and it comes across; leave it blank and the line arrives at $0 to be filled in. Description, quantity and price all stay editable.
Your own business details are used if you have set them up; if not, the estimate opens on the flooring sample. Tick the box and the sample’s usual lines — underlayment, install labor per square foot, removal of the old floor — are added under yours; leave it and the estimate starts with the flooring alone. The flooring estimate template shows how those lines are usually laid out. Doing the walls first? The drywall calculator counts the sheets, and the markup calculator checks the price leaves a margin once the boxes are paid for.
Questions about ordering flooring
How much extra flooring should I buy for waste?
Ten percent is the usual starting point for planks or tile laid straight. Five percent can be enough for one large, square room with few cuts. Diagonal layouts and rooms with lots of corners and doorways commonly need around 15%, and herringbone or chevron 15 to 20% or more. The installation instructions for the product sometimes give their own figure.
How do I calculate how many boxes of flooring I need?
Add up the square feet of every room, multiply by one plus the waste allowance, and divide by the square feet per box printed on the carton, rounding up. For 200 sq ft at 10% waste with 20 sq ft boxes: 200 × 1.10 = 220, and 220 ÷ 20 = 11 boxes.
Should I keep a spare box of flooring?
Many installers suggest it. Flooring lines are discontinued and colors shift between production runs, so a damaged plank or tile in five years is far easier to replace from a box in the garage than from a store. If the waste allowance leaves most of a box over, that box is your spare.
Do I include closets and the area under cabinets?
Include closets and any floor that will be covered. Under fixed base cabinets and kitchen islands is usually left out, since the flooring stops at them — but floating floors have their own rules about cabinets sitting on them, so check the product’s installation instructions before you decide.