Cone Surface Area Calculator
SA = πr² + πrl, where l = √(r² + h²) is the slant height.
Result
General calculation reads
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How to use this calculator
- Enter base radius and height.
- Read SA (with or without base).
About this calculator
A cone's surface has two parts: lateral (curved side) and base (circle). Lateral surface = πr × slant, where slant = √(r² + h²). Total SA = πr² + πr × slant = πr(r + slant). Many real cones are open (party hats, ice cream cones) — use just the lateral. The lateral, when unrolled, is a circular sector of radius = slant, arc-length = circumference of base = 2πr.
Frequently asked
Why slant height for lateral?+
Open-top cone (party hat)?+
Slant from radius and height?+
Cone vs. pyramid SA?+
Real-world cone surfaces?+
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