# Network Calc Propagation Delay Calculator

> Network Calc Propagation Delay Calculator is a paid API for AI agents from network-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Calculates one-way and round-trip propagation delay over fiber, copper, or radio for a given distance or pair of coordinates, plus optional serialization delay.

## Facts

- Endpoint: GET https://network-calc.x402tookit.com/propagation-delay?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/network-calc-propagation-delay-calculator-02b83e90
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_b57UcCRi-Y9TfvzFK6enq

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability network-calc-propagation-delay-calculator-02b83e90
```

Example prompt: What's the one-way and round-trip propagation delay for a fiber link between coordinates 40.7128,-74.0060 (New York) and 51.5074,-0.1278 (London), assuming a route factor of 1.4 and a 10 Gbps link with 1500-byte packets?

## When to prefer this

Use this endpoint when you need precise, physics-based propagation delay estimates for network planning, latency budgeting, or SLA validation. Ideal when you have a known cable distance or geographic coordinates and want one-way/RTT figures broken down by transmission medium. Prefer this over generic ping tools or traceroute when you need theoretical minimums or want to model specific media types (fiber vs copper vs radio).

## Known failure modes

- Missing both distanceKm and coordinate pairs — returns error requesting one or the other
- Invalid medium value outside enum (fiber/copper/vacuum/air) — validation error
- Route factor outside 1-3 range — may be rejected or produce unrealistic results
- Coordinates out of valid lat/lon range — returns validation error
- linkMbps provided without packetBytes may return partial serialization result using default 1500-byte packet

## How this service works

Propagation delay (one way and round trip) over fibre, copper or radio for a distance or two coordinates, plus serialization.

## Output

Returns one-way and round-trip propagation delays in milliseconds, the effective path length in km, serialization delay if link speed is provided, total combined one-way delay, the medium used, route factor, and a human-readable summary. May also include a disclaimer about theoretical vs real-world values.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "lat1": {
       "type": "number",
       "description": "Start latitude (great-circle distance with lat2, lon1, lon2)"
      },
      "lat2": {
       "type": "number",
       "description": "End latitude"
      },
      "lon1": {
       "type": "number",
       "description": "Start longitude"
      },
      "lon2": {
       "type": "number",
       "description": "End longitude"
      },
      "medium": {
       "enum": [
        "fiber",
        "copper",
        "vacuum",
        "air"
       ],
       "type": "string",
       "description": "fiber (default), copper, vacuum or air"
      },
      "linkMbps": {
       "type": "number",
       "description": "Link speed in Mbps for serialization delay"
      },
      "distanceKm": {
       "type": "number",
       "description": "Cable or path length in km (use this, or the four coordinates)"
      },
      "packetBytes": {
       "type": "number",
       "description": "Packet size in bytes for serialization delay (default 1500)"
      },
      "routeFactor": {
       "type": "number",
       "description": "Real cable length divided by great-circle distance, 1 to 3 (default 1; real routes are often 1.3 to 2)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "medium": {
       "type": [
        "null",
        "string"
       ]
      },
      "pathKm": {
       "type": [
        "null",
        "number"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/network-calc-propagation-delay-calculator-02b83e90/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from network-calc.x402tookit.com](https://www.zero.xyz/host/network-calc.x402tookit.com/llms.txt)