Surface Area Calculator

Understanding Surface Area

Surface area is the total area that covers the outer surface of a 3D object. This guide explains how to calculate the surface area of various geometric shapes using key formulas. For volume-related information, see our Volume Calculator, and for flat shapes, refer to the Area Calculator.

🔵 Sphere

  • Formula: SA = 4πr2
  • Example: Truffle with radius 0.325 in: SA = 4π(0.325)2 = 1.327 in2

🔺 Cone

  • Formulas:
    Base = πr2
    Lateral = πr√(r2 + h2)
    Total = πr(r + √(r2 + h2))
  • Example: Cone with r = 1 ft, h = 0.5 ft → Lateral SA = 0.805 ft2

🟫 Cube

  • Formula: SA = 6a2
  • Example: Cube with edge 4 in → SA = 6 × 42 = 96 in2

🧊 Cylindrical Tank

  • Formula: SA = 2πr(r + h)
  • Example: r = 3.5 ft, h = 5.5 ft → SA = 197.92 ft2

📦 Rectangular Tank

  • Formula: SA = 2(lw + lh + wh)
  • Example: Box 3×4×5 ft → SA = 94 ft2

💊 Capsule

  • Formula: SA = 4πr2 + 2πrh
  • Example: r = 0.05 in, h = 0.5 in → SA = 0.188 in2

🟤 Spherical Cap

  • Formula: SA = 2πRh + πr2
  • Example: R = 0.8 ft, h = 0.53 ft → SA = 2.664 ft2

🔻 Conical Frustum

  • Formula:
    End = π(R2 + r2)
    Lateral = π(R + r)√((R – r)2 + h2)
    Total = Sum of both
  • Example: R = 1 ft, r = 0.3 ft, h = 1.5 ft → SA = 10.185 ft2

🥚 Ellipsoid

  • Approx. Formula:
    SA ≈ 4π[(a1.6b1.6 + a1.6c1.6 + b1.6c1.6)/3]1/1.6
  • Example: a = 0.1, b = 0.2, c = 0.35 in → SA ≈ 0.562 in2

⛩ Square Pyramid

  • Formula:
    Base = a2
    Lateral = 2a√((a/2)2 + h2)
    Total = a2 + 2a√((a/2)2 + h2)
  • Example: a = 3 ft, h = 5 ft → SA = 40.321 ft2

📐 Common Area Units

UnitIn Square Meters (m2)
Kilometer²1,000,000
Meter²1
Centimeter²0.0001
Millimeter²0.000001
Micrometer²0.000000000001
Hectare10,000
Mile²2,589,990
Yard²0.83613
Foot²0.092903
Inch²0.00064516
Acre

4,046.86

Related Calculator:
Circle Calculator, Distance Calculator

External Resources:
Surface Area Calculator on Calculator.net

Advertisement