```{eval-rst}
.. currentmodule:: xarray
```

# Converting units

```{eval-rst}
.. ipython:: python
    :suppress:

    import xarray as xr
```

When working with {py:class}`Dataset` or {py:class}`DataArray` objects with
units, we frequently might want to convert the units. Suppose we have:

```{eval-rst}
.. ipython::

    In [1]: ds = xr.Dataset(
       ...:     {"a": ("x", [4, 8, 12, 16])}, coords={"u": ("x", [10, 20, 30, 40])}
       ...: ).astropy.quantify({"a": "m", "u": "s"})
       ...: ds

    In [2]: da = ds.a
       ...: da
```

To convert the data to different units, we can use the
{py:meth}`Dataset.astropy.to` and {py:meth}`DataArray.astropy.to` methods:

```{eval-rst}
.. ipython::

    In [3]: ds.astropy.to(a="cm", u="ks")

    In [4]: da.astropy.to({da.name: "km", "u": "ms"})
```