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Square Footage Calculator

Calculate square footage for rectangular, circular, and triangular areas with unit conversion, perimeter for rectangles, optional cost per square foot, and practical material planning guidance.

Published

Square footage

Total area
120.00 sq ft
Perimeter
44.00 ft

Area is converted to square feet using the original unit conversion factors.

$

Results update as you type.

Worked example

shape: rectangle · length: 12 · lengthUnit: feet · width: 10 · widthUnit: feet · pricePerSqFt: 0

Result: 120.00 sq ft

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Square Footage Calculator

Calculate square footage for rectangular, circular, and triangular areas with unit conversion, perimeter for rectangles, optional cost per square foot, and practical material planning guidance.

Inputs and method

Choose rectangle, circle, or triangle, enter positive dimensions and units, and optionally enter cost per square foot. Dimensions are converted before applying the shape formula; optional cost multiplies unrounded area by the entered rate.

Calculations retain full floating-point precision until the labeled display step. Counts and packages use an explicit upward ceiling only where a whole purchase unit is required.

Interpreting the estimate

Use the result as a planning value and keep input precision consistent with the measurements or source data you have. Small displayed differences can come from final-place rounding; intermediate values are not rounded.

Assumptions and limits

Irregular boundaries, excluded areas, measurement tolerance, and installation waste are not inferred. Break complex spaces into measured shapes. Once the area is known, estimate materials with the tile calculator, concrete calculator, paint calculator, or mulch calculator.

Empty entries, invalid numbers, prohibited negatives, zero denominators, impossible relationships, and unsupported options trigger a validation message instead of a misleading result.

Sources

  • SI Units — authoritative context for the stated definition, rule, model, or applicability boundary.
  • Area measurement — authoritative context for the stated definition, rule, model, or applicability boundary.

Compare Square Footage Calculator with related tools

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Frequently asked questions

Which shape formulas does the calculator use?
Rectangle: length times width; circle: π times the radius squared; triangle: base times height divided by 2. Dimensions are converted to a common unit before the shape formula is applied, and perimeter is shown for rectangles.
How does the optional cost per square foot work?
The entered rate multiplies the unrounded area, and the result is labeled in the same currency and area unit. It is a user-entered planning rate rather than an installed-cost estimate.
Does it handle irregular shapes or material waste?
No. Irregular boundaries, excluded areas, measurement tolerance, and installation waste are not inferred; break complex spaces into measured shapes. Once the area is known, pair it with a material calculator such as tile, concrete, paint, or mulch.

Sources

Related calculators

Square Feet to Square Meters CalculatorConvert square feet to square meters with the exact squared foot-to-meter factor, examples for floor plans and real estate, and a reference table.Land Area CalculatorCalculate rectangular land area from length and width, then compare acres, hectares, square feet, and square meters for land records.Lot Size to Square Feet CalculatorCalculate lot size in square feet from length and width in feet, yards, or meters, with acres, square meters, perimeter, and value.Parking Ratio CalculatorCalculate parking spaces per 1,000 square feet, area per stall, and the surplus or shortage versus a target parking ratio for commercial property analysis.Square Feet ConverterConvert square feet to square meters, square yards, square inches, acres, and hectares with squared-factor guidance for rooms, lots, and materials.Area Converter CalculatorConvert nonnegative area values among metric, international-foot-based, acre, hectare, and square-inch units.

Square Footage Calculator updated at

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