happytails.ai

Circle intersection calculator

Open Circle intersection calculator on Happytails.ai. This view has the same page content and links, with explicit tool capabilities. Read the processing notes before using a tool.

Tool capabilities

{
  "id": "circle-intersection-calculator",
  "category": "calculators",
  "built": true,
  "requirements": "Use the same measurement unit for every coordinate and radius. Coordinates must be finite with magnitudes up to 1,000,000,000. A radius may be zero or between 0.000000001 and 1,000,000,000. Positive Y points up. Results use floating-point arithmetic, not exact symbolic geometry. Cases within the displayed numerical tolerance are treated as tangent; overlap area is measured in the square of your coordinate unit. Coincident circles have infinitely many intersections, represented explicitly rather than as a fabricated point list.",
  "implementation": {
    "fields": [
      {
        "key": "x1",
        "label": "First center X",
        "value": 0,
        "type": "number",
        "min": -1000000000,
        "max": 1000000000,
        "step": "any"
      },
      {
        "key": "y1",
        "label": "First center Y",
        "value": 0,
        "type": "number",
        "min": -1000000000,
        "max": 1000000000,
        "step": "any"
      },
      {
        "key": "radius1",
        "label": "First radius",
        "value": 1,
        "type": "number",
        "min": 0,
        "max": 1000000000,
        "step": "any"
      },
      {
        "key": "x2",
        "label": "Second center X",
        "value": 1,
        "type": "number",
        "min": -1000000000,
        "max": 1000000000,
        "step": "any"
      },
      {
        "key": "y2",
        "label": "Second center Y",
        "value": 0,
        "type": "number",
        "min": -1000000000,
        "max": 1000000000,
        "step": "any"
      },
      {
        "key": "radius2",
        "label": "Second radius",
        "value": 1,
        "type": "number",
        "min": 0,
        "max": 1000000000,
        "step": "any"
      }
    ],
    "input": false,
    "live": true,
    "presentation": "metrics",
    "note": "Use the same unit for coordinates and radii. Positive Y points up; overlap area uses square units. Calculations use floating-point arithmetic. Cases within the reported numerical tolerance are treated as tangent. Zero-radius circles represent points. Your input stays on your device.",
    "experience": {
      "automatic": true,
      "single": false,
      "inputMaxLength": 1000000,
      "inputMode": "text",
      "label": "Your text",
      "placeholder": "Type or paste your input…",
      "help": "Change the input or settings to update your result. Results update as you type. Up to 1,000,000 characters.",
      "helpParts": [
        "Change the input or settings to update your result.",
        "Results update as you type.",
        "Up to 1,000,000 characters."
      ],
      "action": null
    },
    "mode": "automatic",
    "interactive": false
  },
  "execution": "Browser interface",
  "api": null,
  "browser_agent": {
    "supported": true,
    "name": "run_current_tool",
    "discovery": "WebMCP on the human page in a supporting browser",
    "verification": "See audit/API-AUDIT.md; availability is not verification"
  }
}

Page guide

Find where two circles meet and measure their overlap. Enter both centers and radii, then download the diagram and intersection coordinates.

How to use Circle intersection calculator
  1. Enter the X and Y coordinates of each center and both radii.
  2. Read the relationship, intersection count and overlap area. The diagram uses one scale for both circles.
  3. Download the intersection points as CSV, the full calculation as JSON or the diagram as SVG.

Useful next steps

Two circles, one coordinate system

Use the same unit for all six inputs. For two unit circles centered at (0, 0) and (1, 0), the intersections are (0.5, 0.8660254…) and (0.5, -0.8660254…). The overlap area is approximately 1.2283697 square units.

Handle every relationship

Separated circles have no shared area. Contained circles have the area of the smaller circle in common. Tangent circles meet at one point. Identical nonzero circles share infinitely many points. A zero-radius circle is treated as one point.

Keep precision in the download

The visible result uses localized display numbers. CSV and JSON preserve the calculated numeric values. The numerical tolerance is based on floating-point precision and the scale of the circles; this is not exact symbolic geometry.