How many boxes fit in your storage unit?
Enter the cubic meters of your storage unit, choose the box, and get a realistic estimate instantly. Or vice versa: tell us how many boxes you have, and we'll tell you what storage unit you need.
Are you renting a storage unit and don't know if 2 m² is enough or if you need 6 m²? Well, the key is not square meters, but cubic meters... and the size of the box you use. This calculator does the math for you with real cardboard boxes, the kind we ship every day from TeleCajas.
It works both ways. If you already have a storage unit, it tells you how many boxes fit. If you haven't rented one yet, tell it how many boxes you have, and it will recommend the size — so you don't pay for extra meters.
How to calculate how many boxes fit in a storage unit
The formula is simple: usable volume of the storage unit divided by the volume of each box. A medium box measuring 50 × 35 × 35 cm occupies 61 liters, so theoretically 16 fit in 1 m³.
The reality is that you never fill 100%. Between gaps, columns that don't fit, and the aisle to access your belongings, it's reasonable to expect 65-90% utilization. That's why the calculator includes three scenarios: with access aisle (65%), balanced (80%), and filled to maximum (90%).
How many boxes fit in a storage unit based on its square meters
As a quick reference, with a standard height of 2.5 m and a medium box of 61 liters, this is what fits in the most common storage unit sizes in Spain:
| Storage unit | Volume | Medium boxes | Ideal for |
|---|---|---|---|
| 1 m² | 2.5 m³ | 26 - 32 boxes | Documents, archives, and seasonal clothing |
| 2 m² | 5 m³ | 53 - 65 boxes | Contents of a studio or room |
| 3 m² | 7.5 m³ | 79 - 97 boxes | 1-bedroom apartment without large furniture |
| 4 m² | 10 m³ | 106 - 130 boxes | Partial move or e-commerce stock |
| 6 m² | 15 m³ | 159 - 195 boxes | Complete 2-bedroom apartment |
| 8 m² | 20 m³ | 212 - 261 boxes | 3-bedroom apartment or company archive |
| 12 m² | 30 m³ | 318 - 391 boxes | Entire home with furniture |
The ranges go from the scenario with an access aisle (65%) to the balanced one (80%). If you store furniture in addition to boxes, subtract their volume before calculating.
Tips to make better use of space
- Use boxes of the same size: columns remain stable, and you don't lose space between different sizes. Medium 50 × 35 × 35 cm boxes are the most balanced option.
- Heavy at the bottom, light at the top: books and tools in small boxes at the base; clothes and textiles in large boxes at the top.
- Double-wall cardboard for long-term storage: if boxes are going to be stacked for months, reinforced cardboard prevents the stack from collapsing due to humidity and weight.
- Leave an aisle if you'll be accessing often: reserve 40-60 cm for passage. You lose some capacity, but you save yourself from emptying half the storage unit to get to one box.
- Label on two sides: write the contents on at least two visible sides. Your future self will thank you.
Frequently asked questions
A 2 m² storage unit with a height of 2.5 m offers about 5 m³. Between 53 and 65 medium boxes (50 × 35 × 35 cm) can fit, depending on whether you leave an access aisle or not. With small boxes (40 × 30 × 30 cm), the number rises to 90-110 boxes.
It depends on the box size: 1 m³ can theoretically hold about 27 small boxes (36 L), 16 medium boxes (61 L), or 10 large boxes (96 L). In practice, with a realistic stacking of 80%, count on 22, 13, and 8 respectively.
For most storage units, the medium box measuring 50 × 35 × 35 cm is the most balanced: it stacks well and isn't too heavy when full. For books and heavy items, the 40 × 30 × 30 cm box is suitable, and for months of storage, double-wall cardboard boxes. At TeleCajas, you can find them from €1.99 with 24/48h delivery.
With sturdy, well-filled boxes (without empty spaces that can collapse), you can stack columns of 1.80 to 2 m without problems. Always place the heaviest boxes at the bottom and do not exceed 4-5 levels with single-wall cardboard. For higher columns or long-term storage, use double-wall cardboard.
For a 2-3 bedroom apartment, you typically get 30-60 boxes, which, including furniture, require a storage unit of 6 to 10 m². Use the "What storage unit do I need?" mode of this calculator with your number of boxes and, if you don't know it yet, calculate it first with our moving box calculator.
At TeleCajas (telecajas.com), you can find moving and storage boxes starting from €1.99 each, with no minimum order and 24/48h delivery throughout Spain and Portugal, including VAT and shipping. We are packaging specialists with a store in Seville and direct phone or WhatsApp support.
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