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Square Feet Formula:
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The square feet calculation using diameter computes the area of a circle based on its diameter. This formula is essential for determining the surface area of circular spaces or objects.
The calculator uses the circle area formula:
Where:
Explanation: The formula calculates the area of a circle by first finding the radius (half of diameter) and then applying the standard circle area formula πr².
Details: Calculating square feet from diameter is crucial for construction, landscaping, flooring installation, and any project involving circular areas. It helps in material estimation and space planning.
Tips: Enter the diameter in feet. The value must be positive and valid. Height is not required for this calculation as it only determines the area of a circle.
Q1: Why is height not used in this calculation?
A: This formula calculates the area of a circle (2D space), which only requires the diameter. Height would be needed for volume calculations, not area.
Q2: What's the difference between diameter and radius?
A: Diameter is the distance across the circle through its center, while radius is half the diameter (distance from center to edge).
Q3: Can I use this for elliptical shapes?
A: No, this formula is specifically for perfect circles. Ellipses require a different formula involving both major and minor axes.
Q4: How accurate is the π value used?
A: The calculator uses PHP's built-in M_PI constant, which provides π with approximately 14 decimal places of precision, more than sufficient for most practical applications.
Q5: What are common applications of this calculation?
A: Calculating flooring for circular rooms, determining paving area for circular patios, estimating paint coverage for circular surfaces, and planning circular garden beds.