# Pleat calculator

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

## Tool capabilities

| Property | Value |
| --- | --- |
| Tool ID | `pleat-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

Plan repeated knife pleats and download every placement, underfold and fold mark. Bring each fold line to its placement line. Edge allowances remain outside the finished pleated span. Changing units keeps the entered numbers. Calculations run 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 |
| --- | --- | --- | --- | --- |
| `fabricWidth` | Raw fabric width | number | 150 | min=0 max=1000000000 step=any |
| `finishedWidth` | Desired finished pleated width | number | 50 | min=0 max=1000000000 step=any |
| `edgeAllowance` | Unpleated allowance on each raw edge | number | 1 | min=0 max=1000000000 step=any |
| `unit` | Measurement and output unit | select | "cm" | Allowed: mm, cm, m, in, ft, yd |
| `pleats` | Equal knife pleats | number | 10 | min=1 max=1000 step=1 |

### 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

1–1,000 equal knife pleats. Raw fabric after edge allowances must exceed finished width. Box pleats and fabric-thickness effects are not modeled.

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

### Complete machine-readable capability record

```json
{
  "id": "pleat-calculator",
  "category": "calculators",
  "built": true,
  "requirements": "1–1,000 equal knife pleats. Raw fabric after edge allowances must exceed finished width. Box pleats and fabric-thickness effects are not modeled.",
  "implementation": {
    "fields": [
      {
        "key": "fabricWidth",
        "label": "Raw fabric width",
        "value": 150,
        "type": "number",
        "min": 0,
        "max": 1000000000,
        "step": "any"
      },
      {
        "key": "finishedWidth",
        "label": "Desired finished pleated width",
        "value": 50,
        "type": "number",
        "min": 0,
        "max": 1000000000,
        "step": "any"
      },
      {
        "key": "edgeAllowance",
        "label": "Unpleated allowance on each raw edge",
        "value": 1,
        "type": "number",
        "min": 0,
        "max": 1000000000,
        "step": "any"
      },
      {
        "key": "unit",
        "label": "Measurement and output unit",
        "value": "cm",
        "type": "select",
        "values": [
          "mm",
          "cm",
          "m",
          "in",
          "ft",
          "yd"
        ]
      },
      {
        "key": "pleats",
        "label": "Equal knife pleats",
        "value": 10,
        "type": "number",
        "min": 1,
        "max": 1000,
        "step": 1
      }
    ],
    "input": false,
    "live": true,
    "background": false,
    "presentation": "metrics",
    "note": "Plan repeated knife pleats and download every placement, underfold and fold mark. Bring each fold line to its placement line. Edge allowances remain outside the finished pleated span. Changing units keeps the entered numbers. Calculations run 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

Plan evenly repeated knife pleats from raw fabric width, finished width and the number of pleats. Download every fold mark.

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 Pleat calculator

1. Enter your measurements, rates or supplied recipe.
2. Review the quantities, rounding and plan details.
3. Download the result and verify it against your actual materials or a sample.

## Useful next steps

- [Fabric shrinkage calculator](https://happytails.ai/en/calculators/fabric-shrinkage-calculator/) ([Markdown](https://happytails.ai/en/calculators/fabric-shrinkage-calculator.md))

- [Sewing pattern scale calculator](https://happytails.ai/en/calculators/sewing-pattern-scale-calculator/) ([Markdown](https://happytails.ai/en/calculators/sewing-pattern-scale-calculator.md))

## Reserve the edge allowances

The finished pleated span excludes the two raw edge allowances. The remaining fabric is split into repeats. Every knife pleat consumes twice its fold depth; the visible finished pitch is the target span divided by the pleat count.

### Mark placement, underfold and fold lines

With 150 cm raw fabric, 1 cm on each edge, a 50 cm finished span and ten pleats, the finished pitch is 5 cm and fold depth is 4.9 cm. Bring each fold line to its placement line, with the underfold halfway between. All distances are measured from the left raw edge.

### Save the plan

Download the result as CSV, plus a text or JSON report with formulas, values and assumptions. Everything is calculated on your device. Changing units keeps the entered numbers, so check the selected units before using the plan.