Hardwood is one of the most expensive flooring materials by the square foot, which makes over-ordering costly and under-ordering worse — matching a discontinued batch months later is often impossible. Here's how to land on the right number the first time.
The Basic Formula
Square footage = Room length (ft) × Room width (ft)
For rooms that aren't a simple rectangle, break the space into rectangular sections, calculate each separately, and add them together.
Why Waste Allowance Matters More With Hardwood
Unlike carpet or LVP, hardwood planks have a fixed length and can't be seamed or stretched to fit oddly — every cut at a wall or doorway either uses a full plank or wastes the offcut. Standard waste allowance is 10% for a straight lay pattern, rising to 15% for a diagonal layout and higher for herringbone or intricate patterns.
Waste Allowance by Installation Pattern
| Pattern | Waste Allowance | Notes |
|---|---|---|
| Straight lay | 10% | Standard, most efficient use of material |
| Diagonal | 15% | Angled cuts at every wall increase offcuts |
| Herringbone | 15–20% | Every plank is cut at an angle by design |
| Complex / many cutouts | 15–20% | Closets, alcoves, and fixtures add cuts |
Quick Reference: Flooring Needed by Room Size
| Room Size | Floor Area | Straight Lay (10%) | Diagonal (15%) |
|---|---|---|---|
| 10×10 ft | 100 sq ft | 110 sq ft | 115 sq ft |
| 12×12 ft | 144 sq ft | 158 sq ft | 166 sq ft |
| 14×16 ft | 224 sq ft | 246 sq ft | 258 sq ft |
| 16×20 ft | 320 sq ft | 352 sq ft | 368 sq ft |
Coverage Varies by Bundle — Always Check the Box
Unlike some materials with a universal standard, hardwood bundle coverage varies by plank width and length between manufacturers and even between product lines from the same brand. Always check the coverage printed on your specific product's box rather than assuming a standard figure — a 3-inch plank and a 7-inch wide plank cover very different square footage per bundle.
Buy Extra for Future Repairs
Beyond your waste-adjusted total, buy an additional 5–10% and store it flat in a climate-controlled space, ideally in the same room it will eventually patch. Hardwood dye lots and finish batches vary over time — flooring bought even a year later from the "same" product line often doesn't match seamlessly.
Frequently Asked Questions
How much hardwood flooring do I need for a 200 sq ft room? Add 10% waste for a straight lay, so a 200 sq ft room needs about 220 sq ft of hardwood ordered. For a diagonal layout, order closer to 230 sq ft.
Does installation pattern really change how much I need? Yes — diagonal and herringbone patterns waste significantly more material than a straight lay due to the angled cuts required at nearly every row.
Should I buy extra hardwood for future repairs? Yes, buy 5–10% more than your waste-adjusted total and store it flat — matching dye lots years later is often impossible.
Why does bundle coverage vary between products? Plank width and length differ by manufacturer and product line, so a bundle's square footage coverage isn't standardized — always check the specific box.