How much extra flooring should you order?
Waste is a layout and purchasing allowance, not a percentage that fits every room.
Reviewed August 2026 · HomeCostPilot Editorial Team
Start with net measured area
Sketch each room, divide irregular spaces into simple shapes and add their areas. Measure closets and connected areas separately. Record transitions, islands, fireplaces, stairs and fixed objects rather than relying on a listing square footage.
What increases waste
- Diagonal or herringbone layouts
- Pattern matching and centered tile layouts
- Narrow rooms and many doorways
- Short boards or large-format tile
- Damaged pieces and color selection
- Carton quantities that force rounding up
Worked ordering example
A 500-square-foot net area with a 10% planning allowance becomes 550 square feet. If cartons cover 23.8 square feet, divide 550 by 23.8 and round up to a whole carton. The resulting order will be slightly above the percentage because partial cartons generally are not available.
Keep attic stock deliberately
Unused matching material can help with later repairs after a product line or dye lot changes. Confirm storage conditions with the manufacturer; moisture and temperature can damage some products.
Waste does not cover preparation
Underlayment, moisture mitigation, leveling, demolition, transitions and baseboards are separate costs. Use the selected product installation instructions for acclimation, substrate and expansion requirements.