Pad a bounding box by km API

Expands a min/max lat-lon bounding box outward by a buffer distance in km on every side, converting km to degrees with the correct cos(latitude) longitude shrinkage. Answers 'How do I add a 10 km buffer around this bbox?', 'What are the padded bounds for a search radius?'.

Price$0.04per request

MethodPOST

Route/v1/geo/bbox-expand

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

geogisbboxbounding-boxbufferexpandpaddinggeofenceextent

API URLhttps://x402.hexl.dev/v1/geo/bbox-expand

Integration docs

Example request

{
  "minLat": 51,
  "minLon": -0.5,
  "maxLat": 51.6,
  "maxLon": 0.2,
  "padKm": 10
}

Example response

{
  "input": {
    "minLat": 51,
    "minLon": -0.5,
    "maxLat": 51.6,
    "maxLon": 0.2
  },
  "padKm": 10,
  "bbox": {
    "minLat": 50.90956282670429,
    "minLon": -0.6436740065457798,
    "maxLat": 51.69043717329571,
    "maxLon": 0.34367400654582525
  },
  "deltaDegrees": {
    "latitude": 0.090437,
    "longitude": 0.143674
  },
  "interpretation": "Expanded the bounding box by 10 km on each side (±0.09° lat, ±0.144° lon at the box's mid-latitude)."
}

Input schema

{
  "type": "object",
  "required": [
    "minLat",
    "minLon",
    "maxLat",
    "maxLon",
    "padKm"
  ],
  "properties": {
    "minLat": {
      "type": "number",
      "examples": [
        51
      ]
    },
    "minLon": {
      "type": "number",
      "examples": [
        -0.5
      ]
    },
    "maxLat": {
      "type": "number",
      "examples": [
        51.6
      ]
    },
    "maxLon": {
      "type": "number",
      "examples": [
        0.2
      ]
    },
    "padKm": {
      "type": "number",
      "examples": [
        10
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}