Storage unit cost by size
Storage unit prices rise with size but not proportionally. A 10x20 has four times the floor area of a 5x10 but costs roughly three times as much, which makes larger units consistently cheaper per square foot (sq ft) and per cubic foot (cu ft).
- 8 sizes priced
- Per sq ft and per cu ft
- Reviewed August 2026
Price table by size
| Size | Floor area | Standard | Climate-controlled | Per sq ft | Per cu ft |
|---|---|---|---|---|---|
| 5×5 | 25 sq ft | $40–$75 | $55–$95 | $2.30 | $0.287 |
| 5×10 | 50 sq ft | $55–$110 | $70–$140 | $1.65 | $0.206 |
| 5×15 | 75 sq ft | $75–$140 | $95–$175 | $1.43 | $0.179 |
| 10×10 | 100 sq ft | $90–$180 | $115–$230 | $1.35 | $0.169 |
| 10×15 | 150 sq ft | $125–$240 | $155–$300 | $1.22 | $0.152 |
| 10×20 | 200 sq ft | $160–$310 | $195–$380 | $1.18 | $0.147 |
| 10×25 | 250 sq ft | $195–$370 | $235–$450 | $1.13 | $0.141 |
| 10×30 | 300 sq ft | $225–$440 | $270–$530 | $1.11 | $0.139 |
National reference ranges aggregated from published list prices across major US self-storage operators. Standard drive-up or interior units, month-to-month, before promotions, taxes and fees.
What each step up costs
| Step | Extra volume | Extra monthly cost | Cost per extra cu ft |
|---|---|---|---|
| 5x5 → 5x10 | +200 cu ft | +$25 | $0.125 |
| 5x10 → 5x15 | +200 cu ft | +$25 | $0.125 |
| 5x15 → 10x10 | +200 cu ft | +$28 | $0.138 |
| 10x10 → 10x15 | +400 cu ft | +$48 | $0.119 |
| 10x15 → 10x20 | +400 cu ft | +$53 | $0.131 |
| 10x20 → 10x25 | +400 cu ft | +$48 | $0.119 |
| 10x25 → 10x30 | +400 cu ft | +$50 | $0.125 |
Read the last column before you decide to squeeze into a smaller unit. Buying extra space at the margin is remarkably cheap; buying a second unit later is not. The size comparison pages put each step against what it actually holds.
Why bigger is cheaper per square foot
Facility costs are dominated by land, building shell, climate systems and staffing — all of which are close to fixed per building rather than per unit. Doors, walls and corridors are the marginal cost of subdividing, and small units need more of all three per square foot of rentable space.
The practical consequence: two 5x10 units cost noticeably more than one 10x10 with the same total area, and give you two doors to lock and two aisles to walk. Unless you need to separate the contents, take the single larger unit.
Related questions
Which storage unit size is best value?
The 10x15 and 10x20 sit at the best cost per cubic foot in most markets. The 5x5 is the worst — it costs the most per square foot of any size, so needing two of them is a clear signal to move up.
Is a 10x20 twice the price of a 10x10?
No — closer to 1.7 times. A 10x10 runs $90–$180 and a 10x20 $160–$310, for double the space. Compare the sizes.
How do I compare quotes from different facilities?
Convert everything to cost per square foot per month, then add the twelve-month total including admin fee, lock, insurance and one expected rate increase. Facilities compete on the headline rate and recover it elsewhere.