Litres do not tell the whole story
A volume figure describes a cavity, but buyers sell use cases: a pizza diameter, toast count, chicken size or number of trays. Heating elements, fan guards, rack supports and door geometry can reduce practical clearance even when two published capacities look similar.
Convert the customer claim into a fixture
Define the physical items that must fit and the clearances needed for airflow and safe handling. Check tray internal dimensions, rack width and depth, vertical spacing, lowest and highest usable positions, door sweep and handle clearance. Confirm whether accessories can be removed without tipping hot food.
Verify performance at the claimed load
Fitting two trays is not the same as cooking two trays evenly. Run the temperature and food-result validation at the actual loading pattern. If the top tray shields the lower tray or the rear fan creates a strong local zone, the usable marketing claim may need a smaller load or a rotation step.
Use standardized methods where applicable
IEC 60350-1 defines performance measurement methods for household electric ovens and also identifies exclusions for certain small-cavity energy measurements. The exact standard edition and market rules should be confirmed for the product.
- IEC 60350-1:2023: https://webstore.iec.ch/en/publication/69042