# Pace calculator

- Human page: https://happytails.ai/en/calculators/pace-calculator/
- Markdown: https://happytails.ai/en/calculators/pace-calculator.md
- Structured JSON: https://happytails.ai/agents/en/calculators/pace-calculator/index.json
- Visibility: public

## Tool capabilities

| Property | Value |
| --- | --- |
| Tool ID | `pace-calculator` |
| Category | calculators |
| Implementation | Registered implementation. Registration alone is not a production-quality guarantee. |
| Browser execution | Automatic updates after valid input or file selection. |
| Browser processing | Browser; see tool notes for network behavior. |
| HTTP API | Not callable through HTTP. |
| Browser-agent interface | run_current_tool |

### Implementation notes

Calculate pace, finish time or distance. Split times assume a steady pace and include the final partial split. Up to 1,000 splits. Use a distance of at least 1 mm and a pace no slower than 24 hours per km. Decimal seconds are accepted. Changing units keeps the entered numbers. Times display to 0.01 seconds. Everything is calculated on your device.

### Inputs and settings

No free-text input is required. Use the file inputs and/or settings below.

| Setting | Meaning | Control type | Default | Constraints |
| --- | --- | --- | --- | --- |
| `mode` | Calculate | select | "Pace" | Allowed: Pace, Time, Distance |
| `distance` | Distance | number | 5 | min=0 max=1000000 step=any |
| `distanceUnit` | Distance unit | select | "km" | Allowed: km, mi |
| `duration` | Time | text | "25:00" |  |
| `pace` | Pace | text | "5:00" |  |
| `paceUnit` | Pace per | select | "km" | Allowed: km, mi |
| `splitLength` | Split length | number | 1 | min=0 max=1000000 step=any |
| `splitUnit` | Split unit | select | "km" | Allowed: km, mi |

### Browser-agent workflow

1. Open the human page in a browser that supports WebMCP.
2. Discover the interface exposed by that page; use its actual schema.
3. Select files on the page first when the tool requires files.
4. Call `run_current_tool` with valid input and settings.
5. Inspect the returned result or error and the displayed output. Retrieve files from the displayed download links.

Calls do not automatically copy or download results. Browser permissions still apply. Interface availability alone is not proof of successful execution.

### Planning specification

Enter any two of distance, time and pace to calculate the third. Compare minutes per kilometre and mile, speed in km/h and mph, and a split table with the final partial split. Download all splits as CSV. The calculation assumes constant pace; it does not predict changes from terrain, stops or fatigue.

This describes intended requirements. Use the implementation notes, interface schema and observed output to determine current support.

### Complete machine-readable capability record

```json
{
  "id": "pace-calculator",
  "category": "calculators",
  "built": true,
  "requirements": "Enter any two of distance, time and pace to calculate the third. Compare minutes per kilometre and mile, speed in km/h and mph, and a split table with the final partial split. Download all splits as CSV. The calculation assumes constant pace; it does not predict changes from terrain, stops or fatigue.",
  "implementation": {
    "fields": [
      {
        "key": "mode",
        "label": "Calculate",
        "value": "Pace",
        "type": "select",
        "values": [
          "Pace",
          "Time",
          "Distance"
        ]
      },
      {
        "key": "distance",
        "label": "Distance",
        "value": 5,
        "type": "number",
        "step": "any",
        "min": 0,
        "max": 1000000,
        "showWhen": {
          "mode": [
            "Pace",
            "Time"
          ]
        }
      },
      {
        "key": "distanceUnit",
        "label": "Distance unit",
        "value": "km",
        "type": "select",
        "values": [
          "km",
          "mi"
        ],
        "showWhen": {
          "mode": [
            "Pace",
            "Time"
          ]
        }
      },
      {
        "key": "duration",
        "label": "Time",
        "value": "25:00",
        "type": "text",
        "help": "Minutes:seconds or hours:minutes:seconds. For example, 25:00 or 1:25:00.",
        "showWhen": {
          "mode": [
            "Pace",
            "Distance"
          ]
        }
      },
      {
        "key": "pace",
        "label": "Pace",
        "value": "5:00",
        "type": "text",
        "help": "Minutes:seconds per selected unit, for example 5:30.",
        "showWhen": {
          "mode": [
            "Time",
            "Distance"
          ]
        }
      },
      {
        "key": "paceUnit",
        "label": "Pace per",
        "value": "km",
        "type": "select",
        "values": [
          "km",
          "mi"
        ],
        "showWhen": {
          "mode": [
            "Time",
            "Distance"
          ]
        }
      },
      {
        "key": "splitLength",
        "label": "Split length",
        "value": 1,
        "type": "number",
        "step": "any",
        "min": 0,
        "max": 1000000
      },
      {
        "key": "splitUnit",
        "label": "Split unit",
        "value": "km",
        "type": "select",
        "values": [
          "km",
          "mi"
        ]
      }
    ],
    "input": false,
    "live": true,
    "presentation": "metrics",
    "note": "Calculate pace, finish time or distance. Split times assume a steady pace and include the final partial split. Up to 1,000 splits. Use a distance of at least 1 mm and a pace no slower than 24 hours per km. Decimal seconds are accepted. Changing units keeps the entered numbers. Times display to 0.01 seconds. Everything is calculated on your device.",
    "experience": {
      "automatic": true,
      "single": false,
      "inputMaxLength": 1000000,
      "inputMode": "text",
      "label": "Your text",
      "placeholder": "Type or paste your input…",
      "help": "Change the input or settings to update your result. Results update as you type. Up to 1,000,000 characters.",
      "action": null
    },
    "mode": "automatic",
    "interactive": false
  },
  "execution": "Browser interface",
  "api": null,
  "browser_agent": {
    "supported": true,
    "name": "run_current_tool",
    "discovery": "WebMCP on the human page in a supporting browser",
    "verification": "See audit/API-AUDIT.md; availability is not verification"
  }
}
```

## Page guide

Find your pace, finish time or distance, with kilometre and mile splits.

How can we improve this tool?

Report a problem or share an idea.

Please leave out private information. Your message and the tool name go to our team via PostHog.

### How to use Pace calculator

1. Choose Pace, Time or Distance. Enter the other two values, using minutes:seconds or hours:minutes:seconds for time.
2. Choose the split length and unit. Results update on your device and include up to 1,000 splits, including a final partial split.
3. For 5 km in 25:00, the pace is 5:00 per km and 8:02.8 per mile. At 5:30 per km, a 42.195 km marathon takes 3:52:04.35. Copy the summary or download the split table.

## Useful next steps

- [Km to miles](https://happytails.ai/en/unit-converters/km-to-miles/) ([Markdown](https://happytails.ai/en/unit-converters/km-to-miles.md))

- [Time calculator](https://happytails.ai/en/date-time-tools/time-calculator/) ([Markdown](https://happytails.ai/en/date-time-tools/time-calculator.md))

## What to expect

Find your pace, finish time or distance, with kilometre and mile splits. Enter any two of distance, time and pace to calculate the third. Compare minutes per kilometre and mile, speed in km/h and mph, and a split table with the final partial split. Download all splits as CSV. The calculation assumes constant pace; it does not predict changes from terrain, stops or fatigue. Supported results use a distance of at least 1 mm and a pace no slower than 24 hours per km.