Carpet Calculator
Estimate how many square feet or square yards of carpet and padding you may need for bedrooms, hallways, L‑shaped rooms, or stairs. Support for carpet roll width layouts, pattern repeats, and comprehensive cost breakdowns.
To estimate carpet, multiply room length × width for area, then add a 10% waste factor for simple rooms (15% for stairs and halls, 20% for patterned carpet). Carpet is sold by the square yard (1 sq yd = 9 sq ft) in 12 ft or 15 ft rolls — any room wider than the roll needs a seam. A 12×10 ft bedroom is 120 sq ft (about 13.3 sq yd), so with 10% waste you’d order roughly 132 sq ft. Always buy padding new, 1-to-1 with your carpet area.
Standard square or rectangular room. Standard waste factor: 10%.
⚙️ Advanced Options (Roll Width, Pattern Repeat, Pricing Unit)
What This Calculator Does
This carpet calculator helps you estimate how much carpet and padding you may need for a flooring project. It supports L‑shaped rooms, dedicated stair measurements, and automatic price suggestions based on carpet quality. Calculate up to 5 separate room areas at once.
How to Use the Carpet Calculator
- Select your unit system and the room complexity. The complexity automatically adjusts the recommended waste factor.
- Choose Rectangle or L‑Shape for each room. For stairs, toggle the dedicated stair mode and enter step count, tread depth, and riser height.
- Select your carpet roll width and an optional pattern repeat for matching motifs.
- Adjust the waste factor if your room has many complex angles or alcoves.
- Optionally pick a carpet quality tier or enter custom prices for carpet, padding, and labour.
- Click Calculate Carpet Needed.
Carpet Calculator Waste Factor Guide
| Project Type | Recommended Waste Factor | Complexity |
|---|---|---|
| Standard Square Room | 10% | Low |
| Standard Rectangular Room | 10% | Low |
| L‑Shaped Room (single area) | 10‑12% | Low‑Medium |
| Hallways & Corridors | 15% | Medium |
| Stairs (straight runs) | 15% | Medium |
| Winding Stairs & Custom Stairs | 20% | High |
| Patterned Carpet matching | 20-25% | Very High |
Carpet Types Comparison Guide
Different carpet types offer varying levels of durability, comfort, and price. Use this guide to choose the right carpet for your space and budget.
| Carpet Type | Durability | Comfort | Best For | Price Range ($/sqft) | Face Weight (oz/sqyd) |
|---|---|---|---|---|---|
| Berber (Loop) | ★★★★★ | ★★★ | High-traffic areas, basements | $1.50 – $3.00 | 20–30 |
| Plush (Velvet) | ★★★ | ★★★★★ | Bedrooms, formal rooms | $2.50 – $5.00 | 30–45 |
| Frieze (Twist) | ★★★★ | ★★★★ | Family rooms, living rooms | $2.50 – $5.00 | 30–40 |
| Saxony | ★★★ | ★★★★★ | Master bedrooms, low-traffic | $3.00 – $6.00 | 35–50 |
| Cut & Loop | ★★★★ | ★★★★ | Versatile, pattern rooms | $2.00 – $4.50 | 25–40 |
| Commercial Grade | ★★★★★ | ★★ | Offices, rentals, stairs | $1.50 – $3.50 | 20–28 |
Common Questions
Why is carpet sold in square yards?
Does carpet roll width matter?
Can I reuse my existing padding?
How much carpet do I need for stairs?
What is the best carpet padding thickness?
How do I calculate carpet for an L-shaped room?
What is carpet face weight and why does it matter?
Should I choose a 12ft or 15ft carpet roll width?
Pro Tips for Carpet Installation
- Mind the Pile Direction: Carpet fibres have a direction. When joining two pieces, the pile must run the same way, otherwise the seam will look like a different colour.
- Pattern Matching: Patterned carpet requires a larger waste factor. The installer must align the pattern perfectly at every seam, which means cutting off excess.
- Seam Placement: Run seams perpendicular to major windows. Light shining parallel to a seam makes it more visible. Keep seams out of heavy traffic areas.
The Complete Guide to Estimating Carpet and Padding
Planning a carpeting project requires more than just multiplying length by width. The size of the roll, pile direction, pattern repeat, and padding quality all affect how much material you actually need.
Carpet Square Feet vs Square Yards
A common point of confusion is how carpet is measured. Carpet is traditionally sold by the square yard, but many modern retailers will list the price per square foot to make it easier to compare with other flooring types. To convert square yards to square feet, multiply by 9. To convert square feet to square yards, divide by 9.
How Much Carpet Waste Should I Add?
The biggest mistake DIYers make is ordering the exact net quantity. Carpet must be cut to fit perimeters, doorways, and closets. Every cut creates scrap. A 10% waste factor is the absolute minimum for standard rooms. For stairs or pattern matching, bump it to 15‑20%.
Why Carpet Roll Width Matters
Because carpet comes in standard roll widths (usually 12ft or 15ft), any room wider than that will require a seam. If you have a room that is 13ft wide, you can either buy a 15ft wide roll and waste 2 feet, or buy a 12ft wide roll and add a seam using extra carpet length. Place seams in low‑traffic areas or under furniture.
How to Measure Stairs for Carpet
Measuring stairs requires finding the total width of the stairs and the total length (run + rise). Simply multiply the number of stairs by the sum of one stair’s tread depth and riser height, then multiply by the stair width. Add at least 15% waste because pieces will need to wrap around bullnoses and edges.
Carpet Padding & Installation Cost Guide
Carpet padding is essential for comfort and extending the life of your carpet. Good quality padding typically costs between $0.50 and $1.00 per square foot. Never reuse old padding! For installation, labor rates vary wildly by region but expect to pay between $1.00 and $2.00 per square foot for basic installation. Moving furniture, tearing out old flooring, or doing complex stair work will increase this rate.