Measure the Longest Points
Rooms are not always square, so use the greatest usable length and width for planning.
Flooring
Carpet Calculator
Estimate the floor area of a rectangular room for carpet planning.
Carpet Measurements
Enter your room measurements to calculate carpet requirements.
Project Details
meters
meters
sqm
What is this calculator?
A carpet calculator estimates how much carpet is needed for a room before ordering rolls or getting an installer quote. Homeowners use it for bedrooms, family rooms, stair landings, and rental updates where roll width, seams, closets, and waste can change the order.
How does this calculator work?
Step 1: enter room length and width. Step 2: the calculator finds floor area. Step 3: it adds waste or converts the area into an estimated roll or material requirement so you can compare it with carpet roll width and supplier pricing.
Formula
Carpet Area = Room Length x Room Width
Required Carpet = Carpet Area x (1 + Waste Percentage / 100)
Length and width are the finished room dimensions. Waste covers trimming, seams, pattern direction, and fitting into closets or doorways.
Example Calculation
Example: A homeowner is carpeting a 13 ft x 15 ft bedroom. Base area is 195 sq ft. With 10% waste, required carpet is 214.5 sq ft. If the carpet is sold from a 12 ft wide roll, the installer may still need to plan seams or a longer roll length even though the area estimate looks simple.
Common Mistakes
- Ignoring roll width and assuming carpet is bought exactly by square footage.
- Forgetting closets or small connected spaces.
- Not allowing waste for seams, trimming, and pattern direction.
- Measuring wall-to-wall before removing old thick base or transitions.
- Forgetting padding, tack strips, thresholds, and installation supplies.
Frequently Asked Questions
Is carpet ordered by square feet?
Area is the starting point, but carpet is often cut from rolls. Roll width and seam layout can change the final amount ordered.
Should I include closets?
Yes, include closets if they will be carpeted with the same material.
How much carpet waste should I add?
Around 10% is useful for many rooms. Patterned carpet, seams, stairs, or irregular spaces may need more.
Does this include carpet pad?
No. Use the same room area as a starting point for pad, but confirm padding roll sizes and installer requirements.
Why can an installer quote more carpet than the calculator?
The installer may be accounting for roll width, seam placement, pattern matching, and door transitions that an area-only estimate cannot fully capture.
Tips
Include Closets and Recesses
Measure every connected area receiving the same carpet and show it on a simple sketch.
Check the Roll Width
A fixed carpet width can create seams or offcuts that an area-only estimate cannot predict.
Keep Pile Direction Consistent
Pieces should normally face the same direction, which may limit reuse of apparently suitable offcuts.
