Running pace & speed converter API

Convert distance + time into pace (min/km, min/mile), speed (km/h, mph), and predicted 5K/10K/half/full finish times at that pace. Answers 'what pace is 10km in 50 minutes', 'convert pace to speed', 'min per mile from min per km', 'predicted marathon time'.

Price$0.01per request

MethodPOST

Route/v1/health/running-pace

StatusLive

MIME typeapplication/json

Rate limit120/minute

CacheNo cache

healthrunningpacespeedcardiomarathonfitnesscalculator

API URLhttps://x402.hexl.dev/v1/health/running-pace

Integration docs

Example request

{
  "distanceKm": 10,
  "timeMinutes": 50
}

Example response

{
  "paceMinPerKm": 5,
  "paceFormatted": "5:00 /km",
  "paceMinPerMile": 8.05,
  "speedKmh": 12,
  "speedMph": 7.46,
  "inputs": {
    "distanceKm": 10,
    "timeMinutes": 50
  },
  "predictedTimes": {
    "fiveKMin": 25,
    "tenKMin": 50,
    "halfMarathonMin": 105.5,
    "marathonMin": 211
  }
}

Input schema

{
  "type": "object",
  "required": [
    "distanceKm",
    "timeMinutes"
  ],
  "properties": {
    "distanceKm": {
      "type": "number",
      "examples": [
        10
      ]
    },
    "timeMinutes": {
      "type": "number",
      "examples": [
        50
      ]
    }
  }
}

Output schema

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