Storage unit size calculator
A 10 × 10 unit has 100 sq ft of floor. Keep a 30 inch aisle from the door to the back and you have 75 sq ft for your things. Pick a unit, add what you are moving, then drag it around a plan drawn to scale. The planner tells you whether it all fits, what is in the way and how much floor you have left.
Waiting
—
Pick a unit size and add your things to see whether they fit.
- Floor used—
- Floor free—
- Under the ceiling—
- Rough volume—
| Item | Size | On the plan |
|---|
The door is at the bottom. The shaded strip is the aisle, so keep it clear. Drag an item to move it. You can focus objects with the Tab key: arrow keys move the focused object, and the [ and ] keys turn it.
The unit
Facilities rent by these names. A real unit can be a few inches off, so type what you measure below.
Left to right on the plan.
Bottom to top on the plan.
Most units are 8 ft. Measure to the lowest thing up there, such as a beam or a sprinkler pipe.
The aisle from the door
30 in lets you walk in with a box. Zero means no aisle.
Set it to the full depth to reach the back wall.
Up the middle lets you reach both sides. In a 5 ft wide unit, a side aisle leaves one strip you can use.
What is going in
Side to side, at the widest point.
Front to back.
As it will stand in the unit. Zero skips the ceiling check.
What this assumes
- Stacking is not modelled. The plan is the floor. Two items in the same spot count as a clash, even if one could sit on the other. To stack, make the pile one item with the pile's height.
- Every item is a box. A sofa with arms or an L-shaped desk takes the floor of the box around it.
- The door is in the bottom wall, and the aisle starts there. If your door is on a long wall, swap the width and the depth.
- Something in the aisle reads as Tight, not a failure. It goes in, but you cannot reach what is behind it.
- The volume is a rough guide. It adds up every item as a solid box. Boxes pack close to that. A chair or a bike does not.
- Sizes are typical, not yours. The list on the sources page says where each one comes from. Measure what you own and type it in.
How this calculation works
- Unit floor
- Take off the aisle
- Place each item
- Check walls, aisle and overlaps
- Check heights
floor free = unit width × unit depth − aisle width × aisle length − each item's width × depth
The planner draws the unit to scale and puts the door at the bottom. The aisle is a strip from the door toward the back that nothing may stand in. Each item is a box on the floor, either way round.
The three verdicts mean different things. Fits means every item has floor of its own and the aisle is clear. Tight means it all goes in, but something stands in the aisle. Doesn't fit means an item is through a wall, two items share the same floor, or something is taller than the ceiling.
| Unit | Floor | Floor outside the aisle | Volume at 8 ft tall |
|---|---|---|---|
| 5 × 5 ft | 25 sq ft | 13 sq ft | 200 cu ft |
| 5 × 10 ft | 50 sq ft | 25 sq ft | 400 cu ft |
| 10 × 10 ft | 100 sq ft | 75 sq ft | 800 cu ft |
| 10 × 15 ft | 150 sq ft | 113 sq ft | 1200 cu ft |
| 10 × 20 ft | 200 sq ft | 150 sq ft | 1600 cu ft |
| 10 × 30 ft | 300 sq ft | 225 sq ft | 2400 cu ft |
| Item | Width × depth × height | Floor it takes |
|---|---|---|
| Queen mattress, on its side | 80 × 12 × 60 in | 6.7 sq ft |
| Queen mattress, flat | 60 × 80 × 12 in | 33.3 sq ft |
| Three-seat sofa | 84 × 38 × 34 in | 22.2 sq ft |
| Two-seat sofa | 60 × 33 × 30 in | 13.8 sq ft |
| Dresser | 60 × 18 × 34 in | 7.5 sq ft |
| Dining table | 72 × 36 × 30 in | 18 sq ft |
| Fridge | 36 × 34 × 70 in | 8.5 sq ft |
| Washer | 27 × 33 × 39 in | 6.2 sq ft |
| 12 medium boxes | 54 × 18 × 64 in | 6.8 sq ft |
| 4 medium boxes | 18 × 18 × 64 in | 2.3 sq ft |
| Bike | 69 × 24 × 42 in | 11.5 sq ft |
How do you pick a unit size?
Start with the big things. Furniture decides the floor plan. Boxes fill the gaps and go up.
Size guides from the big chains give a rough match. Public Storage puts a studio in a 5 × 10, two small bedrooms in a 10 × 10, a two-bedroom home in a 10 × 15 and a three-bedroom home in a 10 × 20. Those guides don't say how high you stack or whether you keep an aisle. This planner shows the floor, so you can check for yourself.
Try the 1-bedroom example above. With a 30 inch aisle all the way back, two things end up standing in the aisle. Cut the aisle to 5 ft, move it to the left wall and press Pack it again, and it all fits. That is the real trade: a smaller unit costs less a month, and you reach less of it.
Why leave an aisle?
You will want something back before you move out. Packed wall to wall, the thing you need is always at the back. An aisle from the door lets you walk in and reach each side.
Put what you need often near the door, along the aisle. Put the sofa and the bed at the back. Pack it again on the plan does the same: big things first, back wall first. The guide to packing a storage unit covers what to stand on end and what to keep by the door.
If you will not open the unit until moving day, set the aisle to zero. The plan then tells you how much floor the things take, with nothing held back.
What won't get through the door?
The unit can hold a sofa its door cannot pass. On a roll-up door, the rolled door sits above the opening, so the opening can be lower than the ceiling. It can be narrower than the unit too. Measure the opening, not the unit.
Indoor units add a hallway, a corner and often a lift. Long things fail there first. Tip the sofa on end, or take the legs off. The furniture through a door planner turns a sofa through an opening on screen, and the guide to getting a sofa through a door covers what to measure.
What doesn't this planner know?
- Stacking. It works on the floor only. Boxes on a dresser, chairs on a table and a mattress over a sofa all save floor this plan can't see.
- Weight. It won't tell you a stack of books will crush the box under it.
- Odd shapes. Every item is a box. Take the legs off a table and it may need far less room than the plan shows.
- The unit itself. Posts, door tracks, lights and sloped floors take room this plan doesn't draw.
Common questions
What size storage unit do I need for a 1-bedroom apartment?
Public Storage’s size guide puts a studio in a 5 × 10 and two small bedrooms in a 10 × 10, so a 1-bedroom usually lands on a 10 × 10. On the floor alone, the 1-bedroom example on this page leaves two things standing in a 30 inch aisle that runs all the way back. Cut the aisle to 5 feet, move it to a side wall and pack again, and it all fits. Stacking boxes on furniture buys more room.
How tall is a storage unit?
Most are 8 feet tall, though it depends on the facility. Check the door too. On a roll-up door the rolled door sits above the opening, so the opening can be lower than the ceiling.
How wide should the aisle in a storage unit be?
Wide enough to walk in with a box in your hands. This planner starts at 30 inches, the side walkway the bed planner on this site uses. Layout guides quote 36 inches for a main walking route. Go narrower if you only need to reach in.
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