# Baluster spacing calculator

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

## Tool capabilities

| Property | Value |
| --- | --- |
| Tool ID | `baluster-spacing-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

Measure the clear opening between posts and the actual baluster width. All lengths use the selected unit. End gaps and internal gaps are equal. Positions are measured from the opening’s left edge. Enter the maximum gap required for your project; this calculator does not determine building-code requirements. Changing units keeps the entered numbers.

### Inputs and settings

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

| Setting | Meaning | Control type | Default | Constraints |
| --- | --- | --- | --- | --- |
| `opening` | Clear opening | number | 1000 | min=1e-06 max=1000000 step=any |
| `width` | Baluster width | number | 40 | min=1e-06 max=1000000 step=any |
| `maxGap` | Maximum clear gap | number | 100 | min=1e-06 max=1000000 step=any |
| `unit` | Measurement unit | select | "mm" | Allowed: mm, cm, m, in, ft |

### 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

Use the clear opening between the inner faces of the posts, the actual width of each baluster, and your required maximum clear gap. All three measurements use the selected unit. End gaps and internal gaps are equal. Up to 10,000 whole-width balusters and six decimal places per dimension are supported. Some width and gap combinations cannot fit. This tool lays out a straight opening; it does not determine local building-code requirements, structural strength or sloped-stair geometry. Changing units keeps the entered numbers.

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

### Complete machine-readable capability record

```json
{
  "id": "baluster-spacing-calculator",
  "category": "calculators",
  "built": true,
  "requirements": "Use the clear opening between the inner faces of the posts, the actual width of each baluster, and your required maximum clear gap. All three measurements use the selected unit. End gaps and internal gaps are equal. Up to 10,000 whole-width balusters and six decimal places per dimension are supported. Some width and gap combinations cannot fit. This tool lays out a straight opening; it does not determine local building-code requirements, structural strength or sloped-stair geometry. Changing units keeps the entered numbers.",
  "implementation": {
    "fields": [
      {
        "key": "opening",
        "label": "Clear opening",
        "value": 1000,
        "type": "number",
        "min": 1e-06,
        "max": 1000000,
        "step": "any"
      },
      {
        "key": "width",
        "label": "Baluster width",
        "value": 40,
        "type": "number",
        "min": 1e-06,
        "max": 1000000,
        "step": "any"
      },
      {
        "key": "maxGap",
        "label": "Maximum clear gap",
        "value": 100,
        "type": "number",
        "min": 1e-06,
        "max": 1000000,
        "step": "any"
      },
      {
        "key": "unit",
        "label": "Measurement unit",
        "value": "mm",
        "type": "select",
        "values": [
          "mm",
          "cm",
          "m",
          "in",
          "ft"
        ]
      }
    ],
    "input": false,
    "live": true,
    "presentation": "metrics",
    "note": "Measure the clear opening between posts and the actual baluster width. All lengths use the selected unit. End gaps and internal gaps are equal. Positions are measured from the opening’s left edge. Enter the maximum gap required for your project; this calculator does not determine building-code requirements. Changing units keeps the entered numbers.",
    "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 the minimum number of balusters and equal gaps for your opening. Download every edge and center position to mark out the layout.

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 Baluster spacing calculator

1. Measure the clear opening between posts and the width of one baluster.
2. Enter the maximum clear gap for your project and choose the shared measurement unit.
3. Read the baluster count and equal gap. Download the marking positions as CSV or the complete layout as JSON.

## Useful next steps

- [Leather hole spacing calculator](https://happytails.ai/en/calculators/leather-hole-spacing-calculator/) ([Markdown](https://happytails.ai/en/calculators/leather-hole-spacing-calculator.md))

- [Length](https://happytails.ai/en/unit-converters/length/) ([Markdown](https://happytails.ai/en/unit-converters/length.md))

- [Cm to inches](https://happytails.ai/en/unit-converters/cm-to-inches/) ([Markdown](https://happytails.ai/en/unit-converters/cm-to-inches.md))

## Measure the opening, not the whole rail

Measure between the inside faces of the end posts. The layout includes one equal gap at each end and equal gaps between the balusters.

### Mark every position from one end

The position table gives left edges, centers and right edges measured from the left edge of the clear opening. Use one reference end to avoid accumulating rounded gaps.

### Use the gap your project requires

For a 1,000 mm opening, 40 mm balusters and a maximum 100 mm gap, seven balusters leave eight 90 mm gaps. The calculator uses the gap you enter; it does not select a compliant gap for your location.