Storage Unit Sizing Calculator

Work out storage unit sizing instantly with clear inputs, formula shown and shareable results.

About Storage Unit Sizing Calculator

Storage sizing works from volume: standard boxes are about 0.09 cubic metres each, large furniture items around 0.9 and appliances 0.55. Adding an access allowance and dividing by a 2.4 metre stacking height converts volume into the floor area you need to rent.

Formulas

Net volume

Net = Boxes x 0.09 + Furniture x 0.9 + Appliances x 0.55 cubic metres

Floor area

Area = Net volume x (1 + Access allowance %) / 2.4 metre height

Worked example

With the default values below, Storage Unit Sizing Calculator returns Storage unit size required of 7.12. Change any input above and every figure here is recalculated in your browser.

Inputs used

Standard boxes to store: 60
Large furniture items: 8
Appliances: 3
Allowance for access aisle: 20

Results

Storage unit size required: 7.12
Unit size in square feet: 76.7
Total volume including access: 17.10
Net contents volume: 14.25

Step by step

1Values used
2Net volume
3Floor area
4Storage unit size required= 7.12
5Unit size in square feet= 76.7
6Total volume including access= 17.10
7Net contents volume= 14.25

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Should I add an access aisle?

Yes if you need to reach items during the storage period. If it is a sealed long-term store, the allowance can be much smaller.

Can I stack to the full unit height?

Usually to about 2.4 metres safely. Heavier items must go at the bottom, which limits how much of the height is genuinely usable.