Pad is sold in rolls of varying coverage, often around 30 to 40 sq yd; divide the square yards by the roll coverage on the label.
How the carpet calculator works
CarpetCalc works out both layouts. Strips running along one side are that side plus the trimming allowance long; the number of strips is the other side ÷ the roll width, rounded up. Linear feet = strips × strip length, carpet area = linear feet × roll width, and square yards = square feet ÷ 9. It keeps the layout with fewer linear feet (or fewer seams on a tie). Pad = floor area plus the extra you set; tack strip = perimeter − doorways. For stairs, each piece is tread + riser + wrap long, and as many pieces as fit side by side across the roll are cut from each row.
Carpet bought from a 12 ft roll (6″ trimming allowance)
| Room | Floor | Carpet bought | Seams |
|---|---|---|---|
| 10 × 12 ft | 13.33 sq yd | 14 sq yd (10.5 linear ft) | 0 |
| 12 × 12 ft | 16 sq yd | 16.67 sq yd (12.5 linear ft) | 0 |
| 12 × 15 ft | 20 sq yd | 20.67 sq yd (15.5 linear ft) | 0 |
| 12 × 18 ft | 24 sq yd | 24.67 sq yd (18.5 linear ft) | 0 |
| 14 × 16 ft | 24.89 sq yd | 38.67 sq yd (29 linear ft) | 1 |
| 16 × 20 ft | 35.56 sq yd | 44 sq yd (33 linear ft) | 1 |
Real layouts also depend on pile direction, pattern repeat, seam placement and how offcuts can fill closets and doorways, so a store or installer may plan the cuts differently. Patterned carpet needs extra for matching the repeat. Results are estimates: have the room measured before you order.
Frequently asked questions
How much carpet pad do I need?
The floor area plus about 5%. A 14 × 18 room needs about 265 sq ft (29.4 sq yd).
How much tack strip do I need?
The perimeter of the room minus doorways. A 14 × 18 room with one 3 ft doorway needs 61 ft, or 16 four-foot strips.
What thickness of pad?
Check the carpet maker's warranty; many residential carpets call for about 7/16 inch or less and a minimum density.
Is CarpetCalc free?
Yes, with no sign-up or ads.
Are my measurements saved?
Yes, in this browser only.