Paint & Flooring
Flooring Calculator
Find out how much flooring you need for one room or the whole house. This flooring calculator adds up the square footage of every room, subtracts anything you are not covering, adds a waste allowance and tells you how many boxes of laminate, vinyl plank or hardwood to buy, with the cost.
Result
Enter your measurements and press Calculate. What to buy, the working and the cost will appear here.
How to use the flooring calculator
- Add each room as a rectangle (or triangle for angled areas), or enter a known area. Subtract anything you are not covering, such as a kitchen island.
- Pick the flooring type and set the waste: 10% for straight-laid planks, 15% for diagonal or herringbone.
- Enter the coverage per box from the box label.
- Add the price per square foot or per box and press Calculate.
How much flooring do I need?
flooring to buy = floor area × (1 + waste)
boxes = flooring to buy ÷ coverage per box, rounded up
A 15 × 12 ft living room is 180 ft². With 10% waste that is 198 ft²; at 23.4 ft² per box, 8.5 boxes, so buy 9.
Worked example: a living room and hallway in vinyl plank
A 15 × 12 ft living room and a 10 × 4 ft hallway get luxury vinyl plank at $2.79 per ft², 23.4 ft² per box, with 10% waste:
- Room 1: 15 ft × 12 ft = 180 ft²
- Room 2: 10 ft × 4 ft = 40 ft²
- With allowance: 220 ft² × 1.1 = 242 ft²
- Boxes: 242 ft² ÷ 23.4 ft² per box = 10.34 → 11 boxes
Boxes to buy: 11 boxes (257.4 ft² of flooring); Floor area: 220 ft²; With 10% waste: 242 ft²; Estimated cost: $718.15. Open this example in the calculator.
How much extra flooring should I buy?
| Situation | Typical waste |
|---|---|
| Straight lay, simple rectangular rooms | 5–10% |
| Rooms with closets, angles or many doorways | 10–12% |
| Diagonal layout | 15% |
| Herringbone or chevron | 15–20% |
Keep a full box after the job: discontinued floors are hard to match when a board needs replacing.
Flooring types
- Laminate and luxury vinyl plank are sold in boxes of roughly 15–25 ft² and usually click together as a floating floor over an underlayment (often attached).
- Solid hardwood is nailed down and needs time to acclimate; boxes vary in board length, so coverage per box matters.
- Engineered wood can float, be glued or nailed.
- For tile, use the tile calculator; for carpet, the carpet calculator, since carpet is bought off a roll.
What else to buy
- Underlayment (if not attached), sold by the roll at about the floor area.
- Transitions and thresholds at doorways and changes of floor.
- Baseboard or quarter round to cover the expansion gap; measure the room perimeter in linear feet.
Assumptions and limitations
- Room areas are measured wall to wall; closets you are flooring should be added as rooms.
- Box coverage comes from you; the default 20 ft² is only a placeholder.
- Stairs need treads and nosings, which are counted separately.
Flooring questions
How do I calculate how much flooring I need?
Measure each room’s length and width, multiply, and add the rooms together. Add 10% for waste, divide by the square feet per box, and round up.
How many boxes of flooring for 500 square feet?
With 10% waste you need 550 ft². At 20 ft² per box that is 28 boxes (27.5 rounded up); at 23.4 ft² per box, 24 boxes.
Should I buy 10% or 15% extra flooring?
10% for most straight-laid floors, 15% or more for diagonal or herringbone layouts and rooms with many corners.
Formulas, unit conversions and default values are explained on our methodology page. Results are estimates; check manufacturer data and local codes before you buy or build.