Guide · updated
What size storage unit do you actually need
Sizing advice is the same everywhere. What is not the same everywhere is how available each size is, and what it costs — so those columns come from 4,655 real locations rather than from a brochure.
Be clear about what this is. The "what fits" column below is ordinary industry guidance, not something our data can tell you — no listing records what anyone put inside. The availability and price columns are measured. We are separating them because a guide that dresses up common knowledge as proprietary research is the kind of thing you should stop trusting.
What each size actually looks like
| Size | Sq ft | Roughly fits | Locations with it | Typical |
|---|---|---|---|---|
| 5x5 | 25 | A closet. Boxes, a bicycle, seasonal decorations, a few small pieces of furniture. Not a mattress. | 86% | $34 |
| 5x10 | 50 | A studio flat, or the contents of one bedroom. A mattress set on its side, a dresser, boxes, a bike. | 97% | $54 |
| 5x15 | 75 | One bedroom with furniture, or a small flat without appliances. Long and narrow — awkward for bulky items. | 61% | $75 |
| 10x10 | 100 | Two bedrooms, or a full one-bedroom flat including sofa and appliances. The most commonly rented size. | 98% | $94 |
| 10x15 | 150 | Three bedrooms, or a two-bedroom flat with appliances. Fits most of a small house move. | 93% | $118 |
| 10x20 | 200 | A three-bedroom house, or a car plus household goods. Roughly a single garage. | 93% | $149 |
| 10x25 | 250 | A large house move, or a vehicle with room to spare around it. | 47% | $165 |
| 10x30 | 300 | Four to five bedrooms, or two vehicles. Rare, and priced accordingly. | 68% | $208 |
Whether you can actually get one depends on where you are
The column above is national, and availability is not. A size held by a modest share of branches across the country can still be everywhere in one market and nowhere in the next — and the second case is the one that ruins a moving plan, because you find out at the point of booking.
Counted across the 340 markets we price, the 10x25 is the hardest to plan around: absent from 58 of them altogether, and held by under a quarter of the branches in 18 more. The 10x10 is the safest, missing from just 1.
| Size | Markets stocking it | Absent from | Scarce in |
|---|---|---|---|
| 5x5 | 310 | 30 | 1 |
| 5x10 | 336 | 4 | 0 |
| 5x15 | 282 | 58 | 9 |
| 10x10 | 339 | 1 | 0 |
| 10x15 | 335 | 5 | 0 |
| 10x20 | 338 | 2 | 0 |
| 10x25 | 282 | 58 | 18 |
| 10x30 | 303 | 37 | 7 |
So if your move depends on one of the harder sizes, check your own market before you commit to it — every market page lists the sizes actually priced there, and a size missing from that list is missing from the market, not from our data.
Size up, once. The most common regret is a unit you cannot walk into. If you are between two sizes, the larger one usually costs proportionally less per square foot — see the price-per-square-foot data — and leaves you an aisle. Going up two sizes "to be safe" is where that logic stops paying.
Measure the awkward thing, not the volume. Most people who run out of room do so because of one item: a sofa that will not corner, a mattress that cannot be stood on end, a desk that only fits diagonally. Volume estimates rarely fail; single large objects do.
Check availability before you plan around a size. The rightmost columns show how many locations actually stock each size. The rarer ones are not merely dearer — in many markets they simply are not there, which turns a careful plan into a last-minute compromise on moving day.