Flooring calculator

Carpet calculator

Carpet area in square feet or metres, square-yard equivalent, and optional whole-roll or cut conversion.

By Feroz Sheikh · Formula FLOOR-CARPET-001 v1.1.0 · Tested formula

FormulaFLOOR-CARPET-001v1.1.0

Project inputs

Enter your measurements. Switching units converts the same project, including coverage and unit rates. Package yields keep the unit printed beside each field.

Carpet calculator: measurement diagram. Measure the covered surface. Product coverage and cutting allowance determine purchase quantity. — Measure the covered surface. Product coverage and cutting allowance determine purchase quantity. View image

Floor lengthft + inFinished carpet area lengthftinFloor widthft + inFinished carpet area widthftinSelected roll or cut coverageft²Usable net area of one selected roll or quoted cut; used for the purchase-unit comparisonWaste factor%Allowance for seams, pattern matching and cuts

Refine measurements and rates at any time. Your current values are included in the material-list PDF.

Calculated result

277.2ft²

Carpet area including allowance

FormulaFLOOR-CARPET-001

area to order = L × W × (1 + waste); selected units = area to order ÷ stated coverage

252 ft²

Net floor area

30.8 yd²

Square-yard equivalent

2 rolls

Selected rolls or cuts

Planning estimate, not engineering advice. Confirm site measurements and product specifications. Calculation limits.

This calculator returns whole carpet rolls or cuts from room length, width and the roll's stated net coverage. Formula FLOOR-CARPET-001 v1.1.0. Seam and pattern waste stay an input. Stairs and pad are extra lines. Drop the count into an estimate. Confirm the seam layout with your installer.

Measure each finished room as its own rectangle; split L-shaped spaces into rectangles.
Enter one room here, then use Add line for each differently sized room in the same estimate.
Use the exact product's net roll or quoted-cut coverage only for the optional unit comparison.
Confirm roll direction, seams, pattern repeat, stairs and joins with the installer before ordering.

Add your project costs

Enter supplier prices and any labour, equipment or delivery costs. Pick a currency — badges, inputs, and totals follow.

Costs use the carton or square-foot rate you type. Construclytic does not fetch store prices. Underlayment, grout, thinset and labour stay companion lines.

View estimate Quote / invoice Add another item

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How this calculator works

A transparent carpet calculator takeoff.

Feroz SheikhWritten by Feroz Sheikh · founderFormula FLOOR-CARPET-001 v1.1.0 automated checks Oct 3, 2026.

This calculator makes carpet area including your seam and cut allowance the main result, then shows square yards and an optional whole-roll or quoted-cut comparison.

FLOOR-CARPET-001 uses the selected roll’s net coverage and a waste that you can edit. Stairs, seams and pattern match eat more than a rectangle. This is a coverage count, not a stretch-in design.

Worked example. Example: an 18 ft × 14 ft room with 10% allowance needs 277.2 ft², or 30.8 yd². At 180 ft² of usable coverage per selected roll or quoted cut, the comparison rounds to 2 units.

See the example inputs and calculated result

This separate example uses the calculator's starting values in imperial units. It stays unchanged when you edit the tool above. Example rates, yields and dimensions are assumptions, not recommendations for your project.

Carpet calculator: example inputs
Input	Example value
Floor length	18 ft
Floor width	14 ft
Selected roll or cut coverage	180 ft²
Waste factor	10 %

Example result: Carpet area including allowance — 277.2 ft².

area to order = L × W × (1 + waste); selected units = area to order ÷ stated coverage

Use the labelled units above when reproducing this example. To work in metric, switch the calculator to Metric; applicable measurements are converted, while product-specific units remain labelled.

1. Measure each finished room as its own rectangle; split L-shaped spaces into rectangles.
2. Enter one room here, then use Add line for each differently sized room in the same estimate.
3. Use the exact product's net roll or quoted-cut coverage only for the optional unit comparison.
4. Confirm roll direction, seams, pattern repeat, stairs and joins with the installer before ordering.

Field notes that change the number

Measure the rooms that will actually receive this SKU.
Stairs and landings are extra — do not average them into the rectangle.
Pad and tack strip stay off this roll line.

Common mistakes

Ordering from floor area with no seam or pattern waste.
Using a 12 ft roll width on a 15 ft roll product.
Hiding pad inside the carpet yards.

Need the broader workflow? Read the flooring planning guide.

How-to: How to measure carpet for a room

Formula & assumptions

Show your work.

area to order = L × W × (1 + waste); selected units = area to order ÷ stated coverage

Area including allowance is the direct planning answer; the selected roll or cut conversion uses the net coverage you enter.
Waste is added before the square-yard and whole-unit conversions.
This does not optimise roll direction, seams, pattern repeat or joins between rooms; confirm those with the installer.

Formula ID FLOOR-CARPET-001 · version 1.1.0. Automated regression checks passed 2026-10-03 · independent external engineering review is not claimed.

Tested 2026-10-03 by Feroz Sheikh.

Open this quote in 18 months and formula FLOOR-CARPET-001 still explains itself. Calculation method.

MeasureSquare: flooring coverage and layout context Lowe's: carpet measurement calculator

MeasureSquare — carpet layout inputs Lowe's — carpet measurement estimator

Questions

Questions about carpet calculator

Does it optimise carpet seam layout?

No. It reports area and a coverage-based unit comparison. Roll width, direction, seams, pattern repeat and room geometry require a detailed installer takeoff.

How do I total several rooms?

Calculate one rectangle at a time and use Add line for every differently sized room. Split an L-shaped room into non-overlapping rectangles; do not add the overlapping area twice.

Why show both square feet and square yards?

Room dimensions are often measured in feet while carpet may be quoted by square yard. The square-yard result is the area including your allowance divided by 9.

Can I use this for carpet pad?

Use the separate underlayment calculator with product-specific roll coverage.

How do I estimate carpet for a room?

An 18 × 14 ft room with 10% seam allowance and 180 ft² roll coverage returns 277.2 ft². Stairs, landings and pad stay extra lines.

Does a carpet calculator include pad?

No. Pad and tack strip use the flooring underlayment calculator with that product’s roll coverage.

What is the formula ID?

This carpet calculator publishes formula FLOOR-CARPET-001, version 1.1.0. The ID stays on the result and on the estimate line.