> For the complete documentation index, see [llms.txt](https://yagsl.yassrobotics.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://yagsl.yassrobotics.com/reference/standard-conversion-factors.md).

# Standard Conversion Factors

Known-good gearing values for common commercial-off-the-shelf swerve modules

These are known-good `gearRatio`/`diameter` values for common COTS swerve modules. Set them either as the drivetrain-wide default in `modules/physicalproperties.json`, or as a per-module override in a module's own `gearing` field (module-level `gearing` wins if both are present):

```json
"gearing": {
  "drive": { "gearRatio": 6.75, "diameter": 4 },
  "angle": { "gearRatio": 12.8 }
}
```

* `drive.gearRatio`: motor revolutions per wheel revolution, as `X` where the ratio is `X:1`.
* `drive.diameter`: wheel diameter in **inches**.
* `angle.gearRatio`: motor revolutions per full azimuth revolution, as `X:1`.

The config generator at [config.yagsl.com](https://config.yagsl.com) has these built in as presets. You generally won't need to type these by hand, but they're listed here for reference and for teams hand-editing JSON.

## MAX Swerve

| Pinion | `angle.gearRatio` | `drive.gearRatio` | `drive.diameter` |
| ------ | ----------------- | ----------------- | ---------------- |
| 12T    | 46.42             | 5.50              | 3                |
| 13T    | 46.42             | 5.08              | 3                |
| 14T    | 46.42             | 4.71              | 3                |

## Swerve Drive Specialties (SDS)

| Module  | `angle.gearRatio` | `drive.gearRatio` | `drive.diameter` |
| ------- | ----------------- | ----------------- | ---------------- |
| MK4 L1  | 12.8              | 8.14              | 4                |
| MK4 L2  | 12.8              | 6.75              | 4                |
| MK4 L3  | 12.8              | 6.12              | 4                |
| MK4 L4  | 12.8              | 5.14              | 4                |
| MK4i L1 | 21.4285714286     | 8.14              | 4                |
| MK4i L2 | 21.4285714286     | 6.75              | 4                |
| MK4i L3 | 21.4285714286     | 6.12              | 4                |
| MK5i R1 | 26                | 7.03              | 4                |
| MK5i R2 | 26                | 6.03              | 4                |
| MK5i R3 | 26                | 5.27              | 4                |
| MK4n L1 | 18.75             | 7.13              | 4                |
| MK4n L2 | 18.75             | 5.9               | 4                |
| MK4n L3 | 18.75             | 5.36              | 4                |
| MK5n R1 | 26.09             | 7.03              | 4                |
| MK5n R2 | 26.09             | 6.03              | 4                |
| MK5n R3 | 26.09             | 5.27              | 4                |

## Thrifty Swerve

Steering gear ratio is **25:1** for both configurations below (12T pinion, 3" wheel, NEO-driven). Check the gear-ratio chart on your Thrifty Swerve for other pinion/output combinations.

| Output gear | `angle.gearRatio` | `drive.gearRatio` | `drive.diameter` |
| ----------- | ----------------- | ----------------- | ---------------- |
| 18T         | 25                | 15                | 3                |
| 16T         | 25                | 16.9              | 3                |

## Plummer Industries

| Configuration      | `angle.gearRatio` | `drive.gearRatio` | `drive.diameter` |
| ------------------ | ----------------- | ----------------- | ---------------- |
| Corner, Mid Ratio  | 28                | 4                 | 2.5              |
| Corner, High Ratio | 28                | 3.25              | 2.5              |

## Deriving your own

If your module isn't listed, compute the reduction from the module's datasheet: `gearRatio` is motor revolutions per output revolution (drive → wheel, angle → azimuth), and `diameter` is the wheel diameter in inches, measured on a slightly-worn tread (a fresh, un-worn wheel measures larger than it will after a few matches, and using the worn number keeps odometry accurate longer). Overestimating `diameter` makes the robot think it's traveled less than it has, so odometry-driven autonomous routines undershoot; verify against a real drive-straight test as described in [Verify Module Locations](/how-to-guides/verify-module-locations.md).


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://yagsl.yassrobotics.com/reference/standard-conversion-factors.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.