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Carpet Area Calculator.
Calculates the carpet area of a room or space from its length and width, with an optional deduction for walls and other non-carpeted areas.
Your inputs
How it works
- 1
Measure the length and width of the room in feet.
- 2
Enter the percentage of area to deduct for walls, pillars, or other obstructions.
- 3
The calculator multiplies length by width to get the gross area.
- 4
It then subtracts the deduction percentage to give the carpet area.
length * width * (1 - deduction_percent / 100)Frequently asked questions
What is carpet area?
Carpet area is the actual usable floor area inside a room, excluding walls, pillars, and other built-in obstructions.
How do I decide the deduction percentage?
Typically, walls and columns take up about 5-10% of the gross area. For a rough estimate, use 10% unless you have exact measurements.
Can I use this for irregularly shaped rooms?
This calculator assumes a rectangular room. For irregular shapes, divide the space into rectangles and calculate each separately.
Explore this calculator category
Results
Formula checkedEstimate for general guidance only — verify important decisions with an appropriate professional.
How it works
Calculates the carpet area of a room or space from its length and width, with an optional deduction for walls and other non-carpeted areas.
- Measure the length and width of the room in feet.
- Enter the percentage of area to deduct for walls, pillars, or other obstructions.
- The calculator multiplies length by width to get the gross area.
- It then subtracts the deduction percentage to give the carpet area.
Formulas
The math behind this calculator, written out so you can verify the result.
Carpet Area
Multiply the room's length and width to get the gross area, then reduce it by the percentage of space taken up by walls and other non-usable areas.
Example:
Input: Length = 12 ft, Width = 10 ft, Deduction = 10%
Calculation: 12 × 10 × (1 - 0.10) = 120 × 0.90
Result: 108 sq ft
Real-world use cases
Where this calculation shows up in everyday life.
Buying carpet
Determine how much carpet you need to purchase for a room, accounting for waste and obstructions.
Example: A 12x10 room with 10% deduction needs about 108 sq ft of carpet.
Real estate listings
Estimate the carpet area of a property to compare with listed square footage.
Example: Compare advertised carpet area with your own measurements.
Interior planning
Plan furniture layout by knowing the actual usable floor space.
Example: Check if a sofa set fits in the carpet area.
Tips and common mistakes
Tips
- Measure from wall to wall, not including baseboards.
- For irregular rooms, break them into rectangles and sum the areas.
- Always add 5-10% extra carpet for waste and pattern matching.
- Use consistent units (feet or meters) for all measurements.
Common Mistakes to Avoid
- Forgetting to deduct for walls and pillars, overestimating carpet area.
- Using exterior dimensions instead of interior dimensions.
- Mixing units (e.g., feet and inches) without converting.
Assumptions and limitations
- Use the stated inputs and units.
- Results are estimates for planning and education.
- Check measurements and source data before making an important decision.