Moving box sizes
Researched and written by Ashley Davis · Reviewed by Emily Johnson · Last reviewed August 2026
Four sizes cover almost everything. Small, typically 16 by 12 by 12 inches at around 1.5 cubic feet. Medium, typically 18 by 18 by 16 at around 3. Large, typically 18 by 18 by 24 at around 4.5. Extra large, typically 24 by 18 by 24 at around 6. Dimensions vary by manufacturer, and the size names are conventions rather than a standard anyone enforces.
How do you choose between them?
By density, not by what fits. The rule is that the heavier the contents, the smaller the box, which is the opposite of what an empty box invites you to do. Books, tools and tinned goods go in small boxes. Bedding, cushions and coats go in extra large ones. If a packed box is uncomfortable to lift to hip height, the contents were right and the box was too big.
What is the practical weight limit?
There is no printed limit that means anything, because the number depends on the board grade and nobody checks it. The usable rule is what a person can carry: if you cannot lift the box and walk ten paces without changing grip, it is too heavy regardless of what the box could technically hold. A box that has to be dragged will fail at the bottom seam.
How many of each size do you need?
Roughly half your boxes will be medium, a quarter small and a quarter large or extra large, for a typical household. A home with many books shifts toward small; a home with a lot of soft furnishing shifts toward large. These are BestMovers.info planning proportions rather than measured figures, and the count that matters is the total for your home size, which the box hub lists.
Which sizes are hardest to find free?
Large and extra large. Businesses receive stock in boxes sized for what was inside, and most stock is dense, so free boxes skew small and medium. The easiest free large boxes come from appliance and furniture retailers, who receive genuinely bulky goods. Everything below that size is usually available from a liquor store, a bookshop or an office within a week of asking.