basic

Cone Surface Area from Radius and Slant Calculator

A_lateral = π·r·ℓ; A_total = π·r·(r + ℓ).

Compute the lateral (curved) surface area, base area, and total surface area of a right circular cone given its base radius r and slant height ℓ: A_lateral = π·r·ℓ; A_base = π·r²; A_total = π·r·(r + ℓ). Useful for cone-shaped tents, traffic cones, lampshades, and ice-cream cones.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

Inputs

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

A_total = π·r·(r + ℓ).

In depth

Compute the lateral (curved) surface area, base area, and total surface area of a right circular cone given its base radius r and slant height ℓ: A_lateral = π·r·ℓ; A_base = π·r²; A_total = π·r·(r + ℓ). Useful for cone-shaped tents, traffic cones, lampshades, and ice-cream cones.