How do I choose the correct box size?

Work from the items, not the box

The right size is the smallest box that comfortably holds what you plan to store, with some room to spare. Make a list and group items by type: flat documents, jewellery, watches, coins and bars, digital storage devices and anything irregular. For each group, think about how you will store it, because packaging changes the space needed.

A simple sizing method

1. Measure the bulkiest items in the form you will store them: a watch in its box, documents in a folder, coins in tubes.
2. Check the longest flat item. Original documents are better stored flat, so the box must be long and wide enough.
3. Add up the weight of heavy items such as bullion, and compare it with the box's weight limit.
4. Allow for growth if you expect to add to a collection or receive inherited items.
5. Compare your measurements with the box's internal dimensions, not its external size.

Balancing space, cost and convenience

A larger box costs more for the whole rental period. A box that is too small, though, means overcrowding, items that are hard to remove without damage, or an upgrade later. If you are unsure, see whether you can pack items more efficiently first. Removing bulky retail boxes saves space, although some collectors prefer to keep original packaging and papers because they can matter at resale.

Knox's sizes and next steps

Knox publishes the current internal dimensions and weight limits for each size. The internal dimensions and maximum weight for each size are in the table below. If your needs change, ask how moving to a different size works. An admin fee applies when you move to a larger or smaller box. Bring both of your keys to Knox and the change is done the same day, with your rental updated to the price of the new box size. Bring your list and measurements to a facility visit, and the team can help you match them to a box.