Carpet Calculator
Calculate how much carpet you need including linear feet, seam placement, padding, and total installation cost. See also Flooring Calculator and Paint Calculator.
Room Dimensions
Cost Estimates (optional)
How to Measure for Carpet
Measuring for carpet requires understanding that carpet comes in rolls of fixed widths (typically 12 ft or 15 ft). Unlike other flooring that comes in individual pieces, carpet must be cut from these rolls, which affects how much you need to buy. The roll width determines where seams will fall and how much waste is generated.
Carpet Calculation Formula
Total Area = Room Length x Room Width
Area in sq yards = Total Area (sq ft) / 9
Strips Needed = Room Width / Roll Width (rounded up)
Linear Feet = Strips Needed x Room Length
Area with Waste = Total Area x (1 + Waste%/100)
Example Calculation
Room: 15 ft x 12 ft = 180 sq ft (20 sq yd)
Roll width: 12 ft
Strips needed: 12 / 12 = 1 strip (no seams)
Linear feet: 1 x 15 = 15 ft
With 10% waste: 180 x 1.10 = 198 sq ft
Order: 198 sq ft of carpet + 198 sq ft of padding
Seam Placement Guidelines
Seams are unavoidable in rooms wider than the carpet roll. Proper seam placement is critical for appearance and durability:
- Place seams in low-traffic areas away from main walkways.
- Run seams parallel to the primary light source (windows) to minimize visibility.
- Avoid placing seams perpendicular to doorways where they receive heavy foot traffic.
- For patterned carpet, seams must align the pattern, increasing waste.
- A 15 ft wide roll can eliminate seams in rooms up to 15 ft wide.
Carpet Types and Typical Costs
| Carpet Type | Cost (per sq ft) | Cost (per sq yd) | Durability | Best For |
|---|---|---|---|---|
| Berber (Loop) | $2-$5 | $18-$45 | High | High-traffic areas, basements |
| Plush (Velvet) | $3-$7 | $27-$63 | Medium | Bedrooms, formal rooms |
| Frieze (Twist) | $3-$6 | $27-$54 | High | Family rooms, hallways |
| Loop Pile | $2-$5 | $18-$45 | High | Offices, commercial spaces |
| Cut-Loop | $3-$6 | $27-$54 | Medium-High | Living rooms, dens |
| Saxony | $4-$8 | $36-$72 | Medium | Bedrooms, low-traffic areas |
| Shag | $4-$9 | $36-$81 | Low | Bedrooms, accent areas |
* Prices are for carpet material only. Add $0.50-$1.00/sq ft for padding and $0.50-$1.50/sq ft for professional installation.
Frequently Asked Questions
Should I choose 12 ft or 15 ft wide carpet?
Choose the width that minimizes seams in your room. If your room is 13 ft wide, a 15 ft roll eliminates seams entirely. A 12 ft roll would require a seam. Fewer seams means better appearance and less waste.
Do I need carpet padding?
Yes, carpet padding is essential. It extends carpet life by absorbing impact, provides insulation and sound dampening, and makes the carpet feel softer underfoot. Most warranties require proper padding.
How much does carpet installation cost?
Professional carpet installation typically costs $0.50-$1.50 per sq ft ($4.50-$13.50 per sq yd). This usually includes removing old carpet, installing tack strips, stretching, and seaming. Stairs and complex layouts cost more.
What is the best carpet padding thickness?
For most residential carpet, 7/16 inch thick padding with 6-8 lb density is ideal. Berber and low-profile carpet needs thinner, firmer padding (3/8 inch). Too-thick padding can cause carpet to wrinkle and wear unevenly.
How long does carpet last?
Quality carpet lasts 5-15 years depending on type, traffic, and maintenance. Nylon is the most durable fiber (12-15 years), followed by polyester (5-10 years). Regular vacuuming and professional cleaning every 12-18 months extends lifespan.
Can I install carpet myself?
While possible, carpet installation requires specialized tools (knee kicker, power stretcher, seam iron) and skills. Poor installation leads to wrinkles, visible seams, and premature wear. Professional installation is recommended for best results.
How do I calculate carpet for stairs?
For each stair, measure the tread depth plus the riser height, then multiply by the stair width. A typical stair needs about 1.5-2 linear feet of carpet. Multiply by the number of stairs and add 10% for waste.