Flooring Calculator
Add up to three rooms, pick a flooring type and get the square footage, waste allowance, number of boxes and total cost – with or without installation.
Formulas shown on this page · Last reviewed October 2026
Flooring formula
area = Σ (room length × room width)
with waste = area × (1 + waste %)
boxes = with waste ÷ sq ft per box, rounded up
Material cost is calculated on whole boxes because you cannot buy part of a carton. Installation is charged on the room area, not on the waste.
Waste and typical prices by flooring type
| Type | Waste | Material per sq ft | Usually sold as |
|---|---|---|---|
| Laminate | 10% | $1.50–$4 | Boxes of ~20 sq ft |
| Vinyl plank (LVP) | 10% | $2–$7 | Boxes of ~20 sq ft |
| Hardwood | 10–15% | $5–$12 | Boxes of ~20 sq ft |
| Carpet | 10–15% | $2–$6 | Rolls 12 ft wide |
Prices are approximate and vary by region, brand and thickness. Edit the price fields to match your quote.
Practical tips
- Measure each room at its longest and widest points. For L-shaped rooms, split them into rectangles using the extra room fields.
- Do not subtract closets you will floor, but you can leave out kitchen cabinet footprints and fixed islands.
- Keep one or two spare boxes from the same lot for future repairs, as colors vary between production runs.
- Let planks acclimate in the room for 48 hours before installing, as most manufacturers recommend.
Frequently asked questions
How much extra flooring should I buy?
Plan on 10% extra for laminate and vinyl plank laid straight, 10–15% for hardwood, and 15% for diagonal layouts. Complex rooms with many corners can need more.
How many boxes of flooring do I need for a 12x15 room?
A 12×15 room is 180 sq ft. With 10% waste you need 198 sq ft, which is 10 boxes of 20 sq ft each. If you lay it diagonally with 15% waste, 207 sq ft needs 11 boxes.
How much does flooring cost per square foot?
Typical 2026 material prices run about $1.50–$4 for laminate, $2–$7 for vinyl plank, $5–$12 for hardwood and $2–$6 for carpet. Installation adds roughly $2–$8 per sq ft depending on the material.
How is carpet measured?
Carpet is sold by the square yard (9 sq ft) from rolls usually 12 ft wide. A 12×15 room with 10% waste needs 198 sq ft, or 22 square yards. Ask the store to lay out seams before buying.