# Pace Calculator — REST API endpoint `pace-calculator`

Running pace calculator. Give any two of distance, finish time and pace, and it solves for the third, then projects 5K, 10K, half marathon and marathon times at that pace. Times accept mm:ss or h:mm:ss; pace is per kilometre or per mile.

- Category: calculators
- MCP server: https://mcp.findutils.com/ (Streamable HTTP, no API keys, 120 req/min per IP)
- REST endpoint: POST https://api.findutils.com/api/tools/pace-calculator/execute (no API keys, 60 req/min per IP)
- Reference page: https://findutils.com/api/pace-calculator/
- Same tool on the other surface: https://findutils.com/mcp/pace-calculator/

## Call the endpoint (verified example)

```bash
curl -X POST https://api.findutils.com/api/tools/pace-calculator/execute \
  -H "Content-Type: application/json" \
  -d '{
    "distance": 10,
    "time": "50:00",
    "unit": "km",
    "solve_for": "pace"
  }'

# Parameter schema
curl https://api.findutils.com/api/tools/pace-calculator
```

## Input schema

| Argument | Type | Required | Description |
|---|---|---|---|
| `distance` | number | no | Distance in the chosen unit. Needed unless solve_for is "distance". |
| `time` | string | no | Finish time as mm:ss or h:mm:ss. Needed unless solve_for is "time". |
| `pace` | string | no | Pace per unit as mm:ss. Needed unless solve_for is "pace". |
| `unit` | string (km \| mi) | no | Distance unit for both the distance and the pace. Default: `"km"`. |
| `solve_for` | string (pace \| time \| distance) | no | Which value to compute from the other two. Default: `"pace"`. |

Example arguments (verified):

```json
{
  "distance": 10,
  "time": "50:00",
  "unit": "km",
  "solve_for": "pace"
}
```

OpenAPI 3.1 spec: https://findutils.com/api/openapi.json · Interactive docs: https://findutils.com/api/docs/

## Also an MCP tool

```bash
claude mcp add findutils --transport http https://mcp.findutils.com/
```

Then ask the client to call `findutils:pace_calculator`. Full MCP reference: https://findutils.com/mcp/pace-calculator/

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