# Units

Each recipe ingredient has a string unit assigned to it. This is great, but a centralized list of all alowed units with some additional properties has several advantages:

* spelling mistakes are not silently ignored, if you make a mistake in the ingredient unit name, comfyrecipes will warn you that it's not on the units list
* `gram` and `g` can refer to the same unit (using aliases)
* we can tell comfyrecipes unit conversion rates (for example 1000 gram = 1 kilogram) which it can then use for example for calculating prices

This example will use the final example from [Quick Start](quickstart.md).

`🗎 myrecipes/recipes/pancakes.yaml:`
```yaml
{{#include ../../examples/firstrealrecipe.yaml}}
```

```
- myrecipes/
    - recipes/
        - pancakes.yaml
    ...
    - units.yaml (we will be creating this file)
```

If you don't want to write the file manually, we can generate it using:
```sh
$ comfyrecipes generate-units
```

This will generate a minimal units.yaml:

`🗎 myrecipes/units.yaml:`
```yaml
- name: cup
- name: piece
- name: tablespoon
```

Now, let's say we would want to call `tablespoon` just `tbsp`, we can add an alias:

`🗎 myrecipes/units.yaml:`
```yaml
- name: cup
- name: piece
- name: tablespoon
  aliases:
    - tbsp
```

Now we can rename the `tablespoon` unit in the recipe to `tbsp` and it will reference the `tablespoon` unit.

For a full reference for what a recipe yaml can contain, please see the [Units Reference](../reference/units.md)