Carpet, Padding and Installation Cost Calculator
Estimate net floor area, carpet order square yards, roll length, padding, waste, and editable material cost.
How to use the carpet calculator
- Measure the actual project. Break irregular work into separate sections and record finished dimensions consistently.
- Enter the core measurements. The quick view focuses on project geometry; add or subtract sections where the calculator supports multiple areas.
- Review purchasing assumptions. Open Advanced inputs to replace example prices, waste, coverage, density, pack size, minimum order, or delivery assumptions with current project information.
- Calculate and verify. Review the formula, limitations, whole-unit rounding, product instructions, and supplier requirements before purchasing.
Key inputs covered: Carpet roll width, Seam, pattern, and cut allowance, Carpet example price, Padding example price, Installation example price, Area operation, Shape, Length, Width, Border width, and additional project-specific assumptions.
Result coverage: The carpet calculator reports 6 separate quantities so the primary estimate and its supporting purchase or planning values can be checked together.
How the estimate works
Added room areas minus deductions receive the seam/pattern allowance, convert from square feet to square yards, and divide by roll width for an equivalent full-width roll length.
900 ft2 equals 100 yd2 before seam and pattern allowance.
Assumptions, rounding, and limitations
Dimensions are treated as finished measurements. Only deductions and allowances entered above are included. Decimal measurements display to two places; purchase quantities round up when a whole container or piece is required.
- The equivalent roll length is not a cutting plan; room orientation, seams, pattern match, roll direction, stairs, closets, and available roll lengths affect the order.
- Padding specifications and installation methods vary by carpet construction, subfloor, traffic, warranty, and local requirements.
- Have the retailer or installer prepare a seam layout and confirm broadloom width, dye lot, transitions, tack strip, removal, delivery, and labor.
Sources and review
These references support unit conversions and selected planning assumptions. Product instructions and local requirements control the actual project.
Last reviewed: 2026-10-09
Editorial process
BuildPlanCalc publishes the formula, editable assumptions, limitations, and supporting references so the estimate can be checked rather than treated as a black box. See the calculation and review methodology, or report a correction.
Frequently asked questions
Are the results exact?
No. Results are planning estimates based on the dimensions and assumptions entered. Confirm product coverage, site conditions, and ordering rules with the supplier.