Carpet Calculator
Estimate project quantities from your measurements. Confirm technical requirements before making purchases.
Calculate your estimate
Preliminary planning only. Actual requirements depend on site conditions and product specifications.
Plan carpet around the roll direction
- Enter room length along the intended carpet-strip direction, with room width across the strips. Keep both measurements in feet.
- Enter the supplier’s roll width. The calculator rounds the room-width-to-roll-width ratio up to whole strips.
- Choose waste and select Calculate. For an alternative orientation, swap room length and width and compare the two results.
Carpet Calculator: formula and assumptions
Strips = room width ÷ roll width, rounded up. Carpet area = strips × room length × roll width × (1 + waste ÷ 100).
Worked calculation
A 16 × 12 ft room using a 12 ft roll with 10% waste requires 211.2 ft². Increasing the room width to 13 ft requires two strips: 422.4 ft² with the same allowance.
What this estimate includes
Assumes strips run along the room length in one fixed orientation. It does not optimize rotation, reuse offcuts or account for pattern matching, seam allowances or stairs. Roll width must be positive.
Planning details that change the estimate
Carpet ordering follows roll geometry, so the purchase area can be much larger than floor area. In a 16 × 13 ft room, a 12 ft roll requires two full-width strips under this fixed-orientation model. Reversing orientation can change the result, but pile direction, visible seams and pattern alignment may make the smaller number unsuitable. A cutting plan is needed to determine whether offcuts can be reused between rooms. The tool does not optimize that plan.
Carpet Calculator FAQs
Why is carpet area larger than room area?
The estimate uses complete roll-width strips. Unused width is still purchased, and the waste percentage is added afterward.
Does this automatically choose the best direction?
No. Swap the room dimensions to compare orientations, then check seam placement and pile or pattern direction with the installer.
How can I convert the result to square yards?
Divide square feet by nine. This changes the area unit, not the number or length of roll strips.
Are pattern matching and stairs included?
No. Pattern repeats, seam trimming, stairs, alcoves and offcut reuse require a separate cutting allowance or layout.
Continue planning this project
Check usable floor area with the Square Footage Calculator. Compare other finishes using the Flooring Calculator or Tile Calculator; their material allowances do not replace a carpet cutting plan.
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