Carpet Calculator
Calculate how much carpet you need for any room. Enter dimensions, get square footage, and see 2026 carpet cost estimates. Includes a 12x15 ft worked example.
Buying the right amount of carpet requires accurate room measurements and a good understanding of how carpet is sold and installed. Ordering too little means a frustrating return trip to the store and potential dye-lot mismatches; ordering too much wastes money. This calculator converts your room dimensions into square footage, adds a recommended 10% waste allowance for cuts and seams, and estimates your total carpet cost based on the price per square yard or square foot you enter. Use it before visiting a flooring retailer so you arrive informed.
How to Measure Your Room for Carpet
Accurate room measurement is the most important step. Here is how to do it correctly:
Step 1 — Measure the longest dimension. Use a tape measure to find the longest length of the room in feet and inches, wall to wall. Include any alcoves or closet areas you want to carpet.
Step 2 — Measure the widest dimension. Measure the widest width of the room perpendicular to the length, also wall to wall.
Step 3 — Calculate the area. Multiply length × width to get the area in square feet. If your room is L-shaped or has an irregular shape, divide it into rectangles, calculate each, and add them together.
Step 4 — Add a waste allowance. Add 10% to the calculated area to account for cuts, seams, pattern matching, and waste. For rooms with many doorways or diagonal layouts, add 15%.
Step 5 — Convert to square yards if needed. Carpet is traditionally sold by the square yard in the US. Divide your square footage by 9 to get square yards (1 sq yd = 9 sq ft).
Carpet Area Formula
Square Footage = Length (ft) × Width (ft) With Waste = Square Footage × 1.10 Square Yards = Square Footage ÷ 9
For rooms priced per square yard:
Total Cost = Square Yards × Price per Sq Yd
For rooms priced per square foot:
Total Cost = Square Footage (with waste) × Price per Sq Ft
Worked Example — 12 × 15 ft Bedroom
Let's calculate the carpet needed for a standard 12 ft × 15 ft bedroom.
- Room area = 12 × 15 = 180 square feet
- With 10% waste allowance = 180 × 1.10 = 198 square feet
- In square yards = 198 ÷ 9 = 22 square yards
Cost scenarios at different carpet grades:
- Budget carpet ($2/sq ft): 198 × $2 = $396
- Mid-range carpet ($4/sq ft): 198 × $4 = $792
- Premium carpet ($8/sq ft): 198 × $8 = $1,584
Installation adds $1–$4 per square foot on top of material costs.
2026 Carpet Cost Guide
Carpet prices vary based on fibre type, pile height, backing quality, and brand. Here are the 2026 US market ranges:
Carpet Cost by Type
| Carpet Type | Material Cost (per sq ft) | Best For | Durability |
|---|---|---|---|
| Polyester (PET) | $0.75 – $2.50 | Bedrooms, low-traffic areas | 5–10 years |
| Nylon | $1.50 – $5.00 | Living rooms, stairs, high traffic | 12–20 years |
| Triexta (SmartStrand) | $2.00 – $4.50 | Families, pets | 12–15 years |
| Wool | $5.00 – $14.00 | Luxury installs, low traffic | 20–30 years |
| Olefin (Polypropylene) | $0.75 – $2.00 | Basements, outdoor-indoor areas | 5–8 years |
| Berber (loop pile) | $1.50 – $4.00 | Offices, basements | 10–15 years |
Installation Costs (2026 US Average)
- Basic installation (standard rooms, no furniture moving): $1.00 – $2.00 per sq ft
- Standard installation (furniture moving, old carpet removal included): $2.00 – $3.50 per sq ft
- Premium installation (stairs, irregular shapes, pattern matching): $3.00 – $5.00 per sq ft
- Padding / underlayment: $0.30 – $0.80 per sq ft additional
- Old carpet removal and disposal: $0.25 – $0.60 per sq ft additional
Rule of thumb: Material and installation together typically run $3 – $11 per square foot depending on carpet grade and project complexity.
DIY vs Professional Carpet Installation
Professional installation is strongly recommended for most homeowners. Here's why:
- Seam quality: Poor seaming leaves visible lines and frays over time. Professionals use heat-bond seam tape and specialized tools.
- Stretching: Carpet must be stretched tight with a power stretcher. Improperly stretched carpet buckles within 1–3 years.
- Stairs: Stair installation requires wrapping and stapling each step — this is difficult, time-consuming, and risky for DIY.
- Time: Installing carpet in a standard bedroom takes 2–4 hours for a professional; 6–10+ hours for a first-time DIYer.
DIY is reasonable for: Loose-lay carpet tiles, small rooms (under 100 sq ft) with no complex seams, or if you have prior flooring installation experience.
Carpet Buying Tips
- Buy from the same dye lot: Carpet colour can vary between production runs. Order all carpet for connected rooms from the same roll or dye lot.
- Ask about padding: The quality of the carpet pad matters as much as the carpet itself. A good pad (6–8 lb density, 7/16" thick) extends carpet life and improves feel underfoot.
- Get three quotes: Installation costs vary significantly by contractor. Get at least three bids for any room over 200 sq ft.
- Check the warranty: Quality carpet comes with a stain warranty (10–25 years) and a wear warranty (5–15 years). Cheap carpet often has limited or no warranty.
FAQ
Q: How much carpet do I need for a 12x15 room? A: A 12 × 15 ft room has 180 square feet of floor area. With a recommended 10% waste allowance for cuts and seams, you should purchase approximately 198 square feet (22 square yards) of carpet. At a mid-range carpet price of $4 per square foot, materials alone cost approximately $792 before installation.
Q: Is carpet sold by square foot or square yard? A: Carpet in the US is most commonly sold by the square yard, though many retailers now list prices per square foot as well. To convert: divide your square footage by 9 to get square yards. A 200 sq ft room requires approximately 22.2 sq yards. Always confirm the unit your retailer is using before comparing prices.
Q: How much does carpet installation cost per square foot? A: Professional carpet installation in 2026 typically costs $1.50 – $3.50 per square foot for standard rooms, including tack strip installation, padding, carpet laying, and trimming. Stairs, unusual room shapes, old carpet removal, and furniture moving add to the cost. Budget $3 – $7 per square foot total for mid-range carpet plus professional installation.
Q: What is the best carpet for high-traffic areas? A: Nylon is the most durable carpet fibre and is the best choice for high-traffic areas like living rooms, hallways, and stairs. Look for a density rating of 3,000+ (face weight divided by pile height) and a twist level of 5+ turns per inch. Triexta (SmartStrand) is a strong second choice, especially for homes with children or pets, due to its built-in stain resistance.
Q: Do I need carpet padding (underlay)? A: Yes, carpet padding is essential. It extends carpet life by absorbing foot traffic impact, improves underfoot comfort, and adds insulation. Most residential carpet warranties require padding for the warranty to remain valid. The standard recommendation is 7/16" thickness with a 6–8 lb density rating. Higher-traffic areas benefit from denser padding; avoid padding over 1/2" thick on stairs.
Related Calculators
- Home Renovation Cost Calculator — Estimate total renovation costs including flooring, paint, and fixtures.
- Square Footage Calculator — Calculate the area of any room or multi-room layout.
- Hardwood Flooring Calculator — Compare carpet costs against hardwood flooring for the same space.