> ## Documentation Index
> Fetch the complete documentation index at: https://lightdash-mintlify-9d6f9427.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# Pie chart
> Use pie charts to visualize data that adds up to a meaningful whole.
Pie charts can be useful to visualize data that adds up to a meaningful "whole". For example, the split of total revenue across each of our product lines.
To use a pie chart, you need at least one metric and one dimension in your query results. You can add multiple dimensions to create more granular groups in your pie charts.
By default, pie charts are shown in a donut shape (i.e. with the center removed) but you can easily toggle the `donut` toggle to switch between a traditional pie and donut chart.
## Referencing the active granularity in labels
Group labels support a `${table_field.granularity}` placeholder that resolves to the active date granularity (for example `day`, `week`, `month`) — including the granularity selected via [date zoom](/guides/date-zoom). Click the **insert date granularity** icon inside the editable group label field to insert the placeholder without typing it manually. See [Referencing the granularity in chart labels](/guides/date-zoom#referencing-the-granularity-in-chart-labels) for the full syntax and supported labels.
Group labels are per-slice overrides keyed to a specific category value. Date zoom re-buckets the underlying dates (for example, a monthly `2024-07` slice becomes a weekly `2024-07-15` slice), so an override set at one granularity stops matching after a viewer zooms to another and the custom label silently falls back to the raw value.