Choosing the Right Storage Unit Size
Storage unit sizes are measured by width and depth in feet, with most units having 8 foot ceilings. The most common sizes are 5x5, 5x10, 10x10, 10x15, and 10x20. Choosing the right size depends on how much you need to store, whether items are bulky or compact, and how you plan to access them. A unit that is too small forces you to stack items unsafely or rent a second unit, while one that is too large wastes money on unused space.
Storage facilities measure units by interior dimensions, but some variations exist. A 10x10 unit is typically 10 feet wide, 10 feet deep, and 8 feet tall, giving 100 square feet of floor space and 800 cubic feet of volume. However, ceiling heights can vary from 7 to 10 feet depending on the facility, which affects total capacity. Always confirm ceiling height when comparing units, especially if you plan to stack items high.
History and Standards in Storage Unit Sizing
Self storage became popular in the United States in the 1960s and 1970s as suburban homes had less built in storage than older city homes. Early storage facilities used shipping container dimensions, leading to 8 by 10 and 8 by 20 foot units. As the industry grew, 10 foot wide units became standard because they accommodate more furniture and are easier to navigate. Modern facilities offer sizes from 5x5 to 10x30 or larger, with 10 foot widths dominating.
There is no universal standard for storage unit sizing, but most facilities follow similar conventions. Units are labeled by width first, then depth. A 10x20 unit is 10 feet wide and 20 feet deep. Climate controlled units are often in interior hallways and may have slightly smaller dimensions than outdoor drive up units due to building structure. Always verify actual dimensions rather than assuming based on the size label.
Common Storage Unit Sizes Explained
A 5x5 unit is the smallest common size, at 25 square feet. This fits boxes, seasonal items, and small furniture like a chair or nightstand. It is comparable to a walk in closet. A 5x10 unit doubles the space to 50 square feet and fits the contents of a one bedroom apartment, including a mattress, small sofa, and boxes. This is a popular size for college students and temporary storage during moves.
A 10x10 unit offers 100 square feet and is the most popular size. It fits a two bedroom apartment, including major appliances, furniture, and boxes. This size accommodates most household storage needs. A 10x15 unit at 150 square feet fits a three bedroom house with careful packing. A 10x20 unit, at 200 square feet, holds a four bedroom house and can also fit a vehicle. Larger units like 10x25 and 10x30 are for commercial use or entire estate storage.
How to Choose the Right Storage Unit Size
Start by listing everything you plan to store. Measure large furniture pieces and estimate how many boxes you will have. Most moving companies and storage facilities provide online calculators that estimate unit size based on room counts and furniture lists. These tools are helpful but tend to overestimate, so review the results critically. If possible, visit the facility to see units in person, as visualizing the space helps with planning.
Consider how you will access your items. If you need frequent access, choose a larger unit so you can create aisles and keep commonly used items near the front. If items will sit untouched for months or years, you can pack more densely and use a smaller unit. Climate controlled units cost more but protect sensitive items like electronics, wood furniture, and documents from temperature and humidity damage.
Size Comparisons and Practical Differences
A 5x10 unit is twice the size of a 5x5 but costs less than twice as much, making it a better value per square foot. A 10x10 unit is four times larger than a 5x5 and offers much more usable space because the 10 foot width allows for better organization. A 10x20 unit is twice the size of a 10x10, with the extra depth ideal for storing vehicles or creating a workshop space in the front half while keeping boxes in the back.
Floor space does not account for vertical storage. An 8 foot ceiling allows stacking boxes six to seven feet high safely, effectively doubling or tripling usable capacity compared to just the floor. Use sturdy shelving to maximize vertical space and keep heavier items at the bottom. Ceiling height differences between 7 and 10 feet can mean a 20 to 40 percent difference in total cubic footage, so ask about ceiling height when comparing prices.
Regional Variations and Pricing Factors
Storage unit availability and pricing vary by region. Urban areas with high real estate costs charge more per square foot than rural areas. Climate controlled units cost 20 to 50 percent more than standard units but are essential in regions with extreme heat, cold, or humidity. Some facilities offer discounts for long term rentals or promotions for first time customers, so compare prices from multiple locations before committing.
Drive up units on ground level cost more than upper floor units because they offer easier access. If you plan to move items in and out frequently or store heavy equipment, the convenience may justify the higher price. Indoor units in climate controlled buildings often require using an elevator, which can be time consuming but protects belongings better. Weigh access convenience against protection and cost when selecting a unit type.
Practical Tips for Storage Unit Selection
Measure your largest items before choosing a unit size. A king size mattress is 76 by 80 inches and needs a unit at least 7 feet wide if stored on its side. Sofas are often 7 to 8 feet long and require similar clearance. If you plan to store a vehicle, measure it and add a few feet on each side for access. A compact car fits in a 10x15 unit, while a full size truck or SUV needs a 10x20 or larger.
Finally, pack efficiently to maximize space. Disassemble furniture when possible and use boxes of uniform sizes for easier stacking. Label boxes clearly and create an inventory list so you can find items without unpacking everything. Leave a small aisle if you need ongoing access. A storage unit size guide with clear dimensions and capacity estimates helps you choose confidently and avoid paying for unused space or cramming items unsafely into a too small unit.