4×5, 10×5, 5×12, 5×15: how the small sizes compare to a 5×5.
The smallest standard self-storage unit is the 5×5 — 25 sqft, ~200 cubic feet at an 8 ft ceiling. There is no standard 4×5 (you get a 5×5 instead). A 10×5 is just a 5×10 (50 sqft) written width-first. 5×12 is not a standard size — you will be quoted a 5×10 or 5×15. Only 5×5, 5×10 and 5×15 are distinct units Public Storage actually rents in this range.
A 5×5 rents for roughly $45/mo nationally in 2026. Each step up adds floor area but usually costs less per square foot, so a 5×10 is not double the price of a 5×5.
Every small storage size, against the 5×5.
Cubic feet = floor sqft × 8 ft ceiling. “Standard” sizes are distinct units Public Storage rents; non-standard sizes show the real size they round to.
What each search actually gets you.
4×5 storage unit20 sqft · 160 cu ft
not standard → 5x5Public Storage does not rent a 4x5. The smallest distinct unit is the 5x5 (25 sqft). A search for a 4x5 unit will land you on a 5x5 in almost every market.
5×5 storage unit25 sqft · 200 cu ft
standard unitThe smallest standard self-storage unit. This is the size every metro page on this site prices.
5×10 storage unit50 sqft · 400 cu ft
standard unitDouble the floor of a 5x5. The next size up when a 5x5 will not close.
10×5 storage unit50 sqft · 400 cu ft
standard unitA 10x5 is a 5x10 written width-first. Same unit, same 50 sqft. Operators list it as 5x10.
5×12 storage unit60 sqft · 480 cu ft
not standard → 5x10 or 5x15Not a standard Public Storage size. It falls between the 5x10 (50 sqft) and 5x15 (75 sqft); you will be quoted one of those two.
5×15 storage unit75 sqft · 600 cu ft
standard unitA standard long-and-narrow unit. Three times the floor of a 5x5.
Is there a 4x5 storage unit?
No. Public Storage does not rent a 4x5. The smallest standard self-storage unit is the 5x5 at 25 square feet. A search for a 4x5 unit will be served by a 5x5 in almost every market.
What is a 10x5 storage unit?
A 10x5 is a 5x10 written width-first — the same 50-square-foot unit. Operators list it as a 5x10. It holds roughly the contents of one room.
Is there a 5x12 storage unit?
5x12 is not a standard Public Storage size. At 60 square feet it falls between the 5x10 (50 sqft) and the 5x15 (75 sqft), so you will be quoted one of those two.
How big is a 5x15 storage unit?
A 5x15 is 75 square feet and about 600 cubic feet at the standard 8-foot ceiling. Public Storage describes it as holding the contents of a large bedroom or a one-bedroom apartment.