Storage unit sizes

US self-storage units run from 5x5 (25 square feet) to 10x30 (300 square feet), almost always with an 8-foot ceiling. The most rented size is the 10x10, which holds a one to two-bedroom home. Floor area is what facilities advertise; volume is what determines whether your belongings fit.

  • 8 standard sizes
  • 25–300 sq ft
  • 200–2,400 cu ft

Storage unit size chart

Standard US self-storage unit sizes
Unit sizeFloor areaApproximate volume*Usable volumeTypical useMonthly cost
5×525 sq ft200 cu ft170 cu ftPart of one room$40–$75
5×1050 sq ft400 cu ft340 cu ftStudio apartment$55–$110
5×1575 sq ft600 cu ft510 cu ft1 bedroom apartment$75–$140
10×10100 sq ft800 cu ft680 cu ft1–2 bedroom apartment$90–$180
10×15150 sq ft1,200 cu ft1,020 cu ft2 bedroom home$125–$240
10×20200 sq ft1,600 cu ft1,360 cu ft3 bedroom house$160–$310
10×25250 sq ft2,000 cu ft1,700 cu ft4 bedroom house$195–$370
10×30300 sq ft2,400 cu ft2,040 cu ft4–5 bedroom house$225–$440

*Assumes an 8-foot ceiling. Actual usable capacity varies by layout, door clearance, packing density and aisle space. Cost is a national reference range reviewed August 2026.

How storage unit sizes are measured

A storage unit is quoted as width × length in feet. A 10x10 is 10 feet wide by 10 feet deep, giving 100 square feet (sq ft) of floor space. Ceiling height is almost always 8 feet and is rarely advertised, which is why floor area alone is a poor guide: the same 100 sq ft holds 800 cubic feet (cu ft) at 8 ft and 1,000 cu ft at 10 ft.

Two cautions worth carrying into a facility visit. Advertised dimensions are nominal — a "10x10" is frequently 9 ft 6 in by 9 ft 8 in once you measure inside the walls. And the door opening is always narrower than the unit, which is what actually stops a sofa going in. Our measuring guide covers what to record before you rent.

Floor area versus volume

Floor area tells you what you can stand on. Volume tells you what you can store. Because you stack, volume is the number that decides the size, and it is the number every calculator on this site works in. The volume guide shows the arithmetic.

Which size do you need?

Recommended unit by home size, from full item-by-item inventories
Home sizeEstimated volumeRecommended unitFill rate
Studio apartment278 cu ft5x1082%
1 bedroom apartment445 cu ft10x1065%
2 bedroom apartment630 cu ft10x1562%
3 bedroom house1,168 cu ft10x2086%
4 bedroom house1,632 cu ft10x3080%

What are the standard storage unit sizes?

5x5, 5x10, 5x15, 10x10, 10x15, 10x20, 10x25 and 10x30 are the standard US sizes. Some facilities also offer lockers under 5x5 and oversized units above 10x30, but those eight cover almost everything on the market.

What is the most common storage unit size?

The 10x10. It holds a one to two-bedroom home, which matches the most common reason people rent storage — a move, a renovation or a downsize. It is also the size most often booked one step too small.

How tall is a storage unit?

Eight feet in most US facilities. Some newer buildings offer 10 ft ceilings, which adds roughly 25% more usable volume for the same floor area — worth asking about before you size up.

What is the smallest storage unit?

A 5x5, at 25 sq ft and about 200 cu ft. Some facilities also rent lockers of 3x3 or 5x5 with a lower ceiling for documents and small boxes.