Horizon Distance
Calculate how far you can see to the horizon from any height. Returns geometric and radio horizons accounting for atmospheric refraction.
⚡ 1 credit per call
Try it
Fill in the fields below and hit Send.
Why use this
The horizon distance depends on observer height. At eye level (1.8m) you can see about 4.8km. From the top of the Burj Khalifa (828m) that extends to ~102km. LLMs give rough estimates — use this for accurate geometric and radio horizon calculations.
Input
| Field | Type | Required | Description |
|---|---|---|---|
height_m |
number | ✓ | Observer height above ground in metres (must be positive) |
Response
| Field | Type | Description |
|---|---|---|
height_m |
number | Input height in metres |
geometric_km |
number | Geometric horizon distance in kilometres |
radio_km |
number | Radio/optical horizon in kilometres (~15% further due to atmospheric refraction) |
Examples
- 1.8m (eye height) → ~4.8km geometric horizon
- 828m (Burj Khalifa) → ~102km geometric horizon
API Reference
Endpoint
POST https://api.lightningapi.tools/horizon-distanceRequired headers
Authorization: Bearer <apiKey>
Content-Type: application/json
Example request
{
"height_m": 1.8
}
Example response
{
"height_m": 1.8,
"geometric_km": 4.79,
"radio_km": 5.51
}