Carpet Calculator
Estimate broadloom carpet cuts, seams, linear length, order area and cost from room dimensions, roll width, trimming and pattern repeat.
Carpet layout formulas
Cuts = room dimension across the roll ÷ roll width, rounded up.
Base cut length = room dimension along the roll + total trimming allowance.
When the carpet has a lengthwise repeat: matched cut length = ceiling(base cut length ÷ repeat) × repeat.
Linear carpet = cuts × matched cut length. Order area equals linear carpet multiplied by roll width. The automatic option evaluates both room orientations and keeps the one with the lower order area; ties prefer fewer seams.
Planning limit: this is a rectangular broadloom estimate, not a cutting diagram. A professional installer must confirm pile direction, pattern alignment across seams, seam placement, doorways, closets, stairs, irregular shapes and whether offcuts can be reused. Calculate disconnected rooms separately unless an installer supplies a combined layout.
Six calculated examples
| Room and product assumptions | Calculated result |
|---|---|
| 12 × 10 ft room; 12 ft roll; no trim or repeat; automatic | 1 cut along width; 10 linear ft; 120 ft² (13.333 yd²); 0 seams |
| 15 × 20 ft room; 12 ft roll; no trim or repeat; automatic | 2 cuts along length; 30 linear ft; 360 ft² (40 yd²); 1 seam |
| 13 × 10 ft room; 12 ft roll; 18 in repeat; automatic | 1 cut along length; 13.5 linear ft; 162 ft² (18 yd²); 0 seams |
| 15 × 20 ft room; 12 ft roll; 6 in trim; forced along width | 2 cuts of 20.5 ft; 41 linear ft; 492 ft² (54.667 yd²) |
| 5 × 4 m room; 4 m roll; no trim or repeat; automatic | 1 cut along length; 5 linear m; 20 m²; 0 seams |
| 5 × 4 m room; 4 m roll; 64 cm repeat; automatic | 1 cut of 5.12 m; 20.48 m²; 0.48 m² above room area |
How to use the carpet calculator
- Measure the longest room length and width at floor level. Include alcoves only when they belong to the same rectangular layout.
- Copy the actual broadloom roll width and lengthwise pattern repeat from the product specification.
- Enter the installer’s total trimming allowance for each cut. Use zero only when you deliberately want an unadjusted mathematical estimate.
- Use automatic direction for a quantity comparison, or force the required pile direction. Lower material use does not override installation constraints.
- Enter carpet and installation rates in one currency. In US mode, rates are per square yard; in metric mode, rates are per square metre.
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