Storage Unit Size Calculator Formula

Understand the math behind the storage unit size calculator. Each variable explained with a worked example.

Formulas Used

Recommended Unit Size

unit_size_sqft = ceil(sqft_needed / 25) * 25

Estimated Monthly Cost

monthly_cost = ceil(sqft_needed / 25) * 25 * monthly_rate_per_sqft

Annual Cost

annual_cost = ceil(sqft_needed / 25) * 25 * monthly_rate_per_sqft * 12

Variables

VariableDescriptionDefault
rooms_of_stuffRooms of Furniture/Stuff3
monthly_rate_per_sqftRate per Square Foot(USD/sq ft/mo)1.5
sqft_neededDerived value= rooms_of_stuff * 50calculated

How It Works

Choosing a Storage Unit Size

A general rule is that one room of furniture needs about 50 square feet of storage space (assuming standard 8-foot ceilings in the unit).

Guideline

Square Feet = Rooms x 50

Common unit sizes: 5x5 (25 sq ft, closet), 5x10 (50, half room), 10x10 (100, 2 rooms), 10x15 (150, 3 rooms), 10x20 (200, 4 rooms), 10x30 (300, full house).

Worked Example

Storing 3 rooms of furniture at $1.50/sq ft/month.

rooms_of_stuff = 3monthly_rate_per_sqft = 1.5
  1. 01Space needed = 3 x 50 = 150 sq ft
  2. 02Rounded up = 150 sq ft (10x15 unit)
  3. 03Monthly cost = 150 x $1.50 = $225
  4. 04Annual cost = $225 x 12 = $2,700

Ready to run the numbers?

Open Storage Unit Size Calculator