Look in the model's specifications, rating information or freezing-food instructions. The figure is normally identified as freezing capacity, not simply storage litres.
What the observation tells you
A retailer summary may omit the conditions needed to achieve the stated result. Some instructions specify a particular mode or loading position. The number for a similar-looking larger model should not be used as a substitute.
A useful next step
Use the complete model reference and retain the applicable page of the instructions. Plan the batch around that information. If it is unavailable, ask the manufacturer rather than estimating capacity from the number of drawers.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.