calc.engineer / General & Math / Circumference

Circumference v1.0.0

Calculate the circumference and area of a circle given either a radius or diameter. Provide one or both; if both are given, radius takes precedence. Returns circumference (C = 2πr), area (A = πr²), and both radius and diameter for completeness. Common in mechanical engineering (pulley systems, pipe sizing), electronics (antenna loop calculations, coil winding), civil engineering (manhole covers, circular foundations), and everyday measurement tasks.

The radius of the circle (takes precedence over diameter)
The diameter of the circle
Fill in the inputs and Compute to see the structured result.

From an agent (MCP) or the API

curl -X POST https://calc.engineer/api/circumference \
  -H "Content-Type: application/json" \
  -d '{"radius": …, "diameter": …}'

MCP: connect to https://calc.engineer/mcp and call circumference.

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