Storage Unit Size Calculator
Estimate the storage unit size you need from the boxes, furniture and appliances you plan to store — and see the recommended unit.
How it works
Volume = boxes × 3 + furniture × 35 + appliances × 25 (cu ft) · Floor needed = volume ÷ 8 ft stack × 1.35 access factor · Unit = smallest size ≥ floor needed
Storage units are rated by floor area, but what you actually store is a volume, so the estimate stacks your belongings to about eight feet and then adds room to walk in and reach things. Boxes, furniture and appliances have very different volumes, so counting them separately is far more accurate than guessing a unit size. The result is the smallest standard unit that comfortably fits the load.
Worked example
Thirty boxes (90 cu ft), eight furniture items (280 cu ft) and two appliances (50 cu ft) total 420 cu ft. Stacked eight feet high that is 52.5 sq ft, and with a 35% access allowance about 71 sq ft — so a 5×15 ft (75 sq ft) unit is the right call.
Frequently asked questions
What size storage unit do I need?
Estimate the volume of everything you are storing, allow for stacking and a walkway, and pick the smallest unit that fits. As a rough guide, a 5×10 holds a studio, a 10×10 a one-bedroom, and a 10×20 a full house of two or three bedrooms.
Should I size up or down?
Size up if you need frequent access (you will want aisles) or if the items are awkwardly shaped. Size down to save money if the contents are mostly boxes that stack neatly and you rarely need to get in.
Does unit height matter?
Yes. Most units have roughly 8-foot ceilings, and this estimate assumes you stack to that height. If a unit has lower clearance or you cannot stack safely, you will need more floor area than the calculation suggests.
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This calculator is for educational purposes. Double-check important results before acting on them.