# `cube_cell_volume()`
**Category:** Grid geometry
**Status:** stable

## Purpose
Combine cell area and layer thickness into volume.

## When to use
Use it when its declared input and output match the workflow. Prefer a narrower selection before any operation that may materialise values.

## When not to use
Do not use it to calculate `spatind` indicators or to bypass coordinate, CRS, unit, and provenance checks.

## Real signature
```r
cube_cell_volume(x, depth_bounds = NULL, unit = c("m3", "km3"))
```

## Arguments
- `x`: see the installed Rd manual for validation and defaults.
- `depth_bounds`: see the installed Rd manual for validation and defaults.
- `unit`: see the installed Rd manual for validation and defaults.

## Input and output
Input: **ocean_cube**. Output: **array**.

## Backend support
Memory: **TRUE**. NetCDF: **TRUE**. Backend operations retain read-only semantics; materialisation is explicit.

## Dimensional effect
Preserves the relevant cube contract or returns metadata/geometry without silently dropping axes.

## Metadata
Units, coordinates, provenance, masks, and QA metadata are retained or reported where meaningful.

## Minimal executable check
```r
library(oceancube)
stopifnot(is.function(oceancube::cube_cell_volume))
names(formals(oceancube::cube_cell_volume))
```

## Example in a workflow
Typical position: `cube_cell_area + cube_layer_thickness` → `cube_cell_volume()` → `integration`. See the workflow scripts for a checked end-to-end example.

## Frequent errors and limitations
Invalid dimensions, selectors, units, CRS, source-file identity, optional dependencies, or unsupported grids are rejected explicitly. Read the function Rd page for exact diagnostics.

## Related functions
Previous: `cube_cell_area + cube_layer_thickness`. Next: `integration`.