Square Inches Calculator
Calculate area in square inches for rectangles, circles, and triangles. Convert between square inches, square feet, square meters, and other area units.
Step 1: Select Shape
Understanding Square Inches
Square inches measure area. 1 square inch is the area of a square with 1-inch sides. Conversions: 144 sq in = 1 sq ft, 1,550 sq in = 1 sq m, 6.45 sq cm = 1 sq in.
Step 2: Calculation Options
Area Formulas
Rectangle: Area = Length × Width
Circle: Area = π × Radius²
Triangle: Area = ½ × Base × Height
Trapezoid: Area = ½ × (Base1 + Base2) × Height
Square Inches Calculation Results
Area in Square Inches
Area Unit Comparison
| Unit | Abbreviation | Square Inches | Equivalent Area | Common Use |
|---|
Area Calculation Formulas
Rectangle / Square
Formula: Area = Length × Width
Example: Length = 10 in, Width = 8 in → Area = 10 × 8 = 80 in²
Circle
Formula: Area = π × Radius² (π ≈ 3.14159)
Example: Radius = 5 in → Area = 3.14159 × 5² = 78.54 in²
Triangle
Formula: Area = ½ × Base × Height
Example: Base = 6 in, Height = 4 in → Area = 0.5 × 6 × 4 = 12 in²
Trapezoid
Formula: Area = ½ × (Base1 + Base2) × Height
Example: Base1 = 8 in, Base2 = 6 in, Height = 5 in → Area = 0.5 × (8 + 6) × 5 = 35 in²
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