Trunk comparison: Ford Focus vs Kia Ceed

Most Important Difference (>10%)
Notably, the depth of the trunk (loading edge to trunk floor) stands out: the Ford Focus has +2.8 in or +64% more depth than the Kia Ceed. This practically means more usable cargo volume below the loading edge and thus better possibilities to store taller or bulky items in the footwell behind the loading edge.
The downside is that the loading point is lower, and items must be moved further down when loading and unloading — access and removal of heavy cargo can therefore be more cumbersome.
Other Differences (under 10%) and Usability
The remaining differences are minor: with the seats folded down, the Ford Focus is only 0.4 in (1%) longer, while with the first row upright, the Kia Ceed is 0.8 in (3%) longer. The trunk opening of the Ford is 2 in (7%) higher, which can slightly ease sliding in tall items, but the practical effect remains small.
The loading edge of the Ford is 1.2 in (5%) higher above the road, making lifting during loading slightly more strenuous. The width at the narrowest point is 0.8 in (2%) greater in the Kia; this can be a small advantage for very wide loads. The width of the trunk opening is the same for both models.
Conclusion: For significantly more usable depth volume and better accommodation of taller/bulkier items, the Ford Focus is clearly advantageous. For everyday situations with normal luggage loads and lighter loading and unloading, the differences between the models are mostly minor.