How to Choose the Right Storage Unit Size

A practical guide to storing your belongings more safely, efficiently, and with fewer costly mistakes.

Written by Michaela Pinga | Updated 31 March 2026

Self Storage Tips & Solutions costs size

Picking the proper storage unit size saves you money and hassle. Get it wrong, and you’ll either pay for space or struggle to fit your belongings. This guide helps you find the perfect size for your needs.

Understanding Storage Unit Sizes

Storage units range from 25 sq ft lockers to 300+ sq ft warehouse spaces. Each size suits different storage needs and budgets. Storage units vary in height, typically around 10 ft., except for lockers, which are 3 ft. high.

25 sq ft – Small Closet Contents

This compact unit fits the contents of a home closet. Store extra mattresses, boxes filled with clothes, books, files, and other small items. Perfect for students or anyone decluttering one room. A 25 sq. ft. unit is ideal for storing the contents of a studio flat.

35 sq ft – Garden Shed Size

At approximately 7 feet x 5 feet, this unit matches a standard garden shed. Great for storing the contents of a one-bedroom flat and holds around 35 medium boxes. Ideal for small flat moves or seasonal storage.

50 sq ft – Half a Car Garage

Usually measuring 5ft x 10ft or 10ft x 5ft, this space is equivalent to half the size of your car garage. Comfortably fits all contents of a studio apartment, including mattresses, furniture, office equipment, and decorative items.

75 sq ft – Two Bedroom Townhouse

This size accommodates contents from a two-bedroom townhouse. Perfect when transitioning between homes. Holds mattresses, cabinets, bookcases, large appliances, files, and more.

100 sq ft – Standard Garage Size

Equivalent to a standard home garage, this unit stores items from your office or two-bedroom home. Popular for both personal and business storage needs. A 100 sq. ft. unit is about the size of a single garage and is ideal for a medium office move.

150 sq ft – Three Bedroom House

Plenty of room for a three-bedroom house’s contents. Fits complete dining sets, big screen TVs, and other large furniture or appliances you need to store. A 200 sq. ft. unit can store the contents of a four-bedroom house.

200 sq ft – Vehicle Storage Plus

Large enough for vehicles like boats and cars, with space remaining for outdoor equipment, boxes, and small personal items. Ideal for seasonal vehicle storage.

Van Size Reference Points

Understanding van capacities helps estimate your storage needs:

Transit Van: Holds approximately 35 sq ft worth of belongings – perfect for moving double bedroom contents into a 35 sq ft storage unit.

Luton Van: Accommodates around 75 sq ft worth of space. If you need a Luton van for your move, you’ll likely need a 75 sq ft storage unit.

These van comparisons give you a practical way to visualise how much space you need.

Room-by-Room Planning

Studio Flat Storage

A 50 sq ft unit typically handles everything from a studio flat. This includes your bed, small sofa, desk, wardrobe contents, kitchen items, and personal belongings. A 50 sq. ft. unit is approximately the size of half a single garage.

One Bedroom Flat

Most one-bedroom flats require 35-75 sq ft, depending on the quantity of furniture. A furnished flat with numerous belongings requires a larger space, whereas a minimally furnished space can fit in as little as 35 sq ft. A 35 sq. ft. storage unit is suitable for the contents of a double bedroom, including a double bed and wardrobe.

Two Bedroom House

Plan for 75-100 sq ft for a typical two-bedroom house. Larger homes with substantial furniture collections might need 150 sq ft.

Three Bedroom House

A 150 sq ft unit accommodates most three-bedroom houses, including dining room furniture, multiple bedroom sets, and living room contents. A regular garage size is about 100 sq. ft. and can hold the contents of a three-bedroom house (excluding kitchen appliances).

Vehicle Storage Requirements

Car Storage

Standard cars need approximately 100 sq ft, but many facilities offer dedicated vehicle storage areas. Check if your facility offers drive-up access for more effortless loading.

Motorcycle Storage

Motorcycles fit comfortably in units ranging from 25 to 50 sq ft, depending on additional gear storage needs.

Boat Storage

Small boats require units of 200 sq ft or more. Larger vessels need 250-300 sq ft spaces. Many facilities offer specialist boat storage with appropriate access.

Seasonal and Rotational Storage

Holiday Items

Christmas decorations, summer furniture, and seasonal clothes typically need 25-35 sq ft. A garden shed-sized unit handles most families’ seasonal storage.

Sports Equipment

Bicycles, golf clubs, skiing gear, and camping equipment vary in space requirements. Factor in awkward shapes when calculating needs.

Toy Rotation

Families often store toys in rotation. A 25 sq ft unit accommodates several boxes of toys, keeping your home tidy whilst maintaining variety for children.

Box Calculations

Medium-sized boxes stack efficiently and protect belongings. Here’s what different unit sizes accommodate:

• 25 sq ft: 15-20 medium boxes plus small furniture
• 35 sq ft: 35 medium boxes (as specified in our size guide)
• 50 sq ft: 50-60 medium boxes plus furniture
• 75 sq ft: 75-90 medium boxes plus larger items

Business and Office Storage

Document Storage

Businesses storing files and documents often start with 25-50 sq ft units. Consider future growth when selecting size.

Inventory Storage

Retail businesses need larger spaces. Calculate based on stock levels and seasonal variations.

Equipment Storage

Office furniture, computers, and equipment require careful planning of space. Dismantle desks and shelving to maximise space.

Making Your Decision

Assess Your Belongings

Walk through your space, room by room. List furniture, boxes, and loose items. Be realistic about quantities.

Consider Access Needs

If you require regular access, opt for a slightly larger unit with clear walkways. Cramped units make retrieval difficult.

Factor in Growth

Your storage needs might increase. Starting with a slightly larger unit often proves more economical than upgrading later.

Budget Considerations

Larger units cost more, but they provide greater convenience. Balance your budget against accessibility and future needs.

Common Sizing Mistakes

Underestimating Space

Belongings always take up more space than expected. Add 20% to your initial estimate.

Forgetting Odd-Shaped Items

Bicycles, golf clubs, and garden tools don’t pack neatly. Account for these awkward items.

Ignoring Vertical Space

Stack boxes to ceiling height where safe. Use shelving to maximise vertical storage.

Poor Access Planning

Don’t pack units solid. Leave walkways for accessing items at the back.

Professional Guidance

Storage facility staff provide valuable sizing advice based on experience. Most facilities offer complimentary consultations to help you select the ideal size.

Site Visits

Visit facilities to see actual unit sizes. Photos don’t always accurately convey real dimensions.

Upgrade Options

Most facilities allow size changes. Begin with your best estimate, then adjust it as needed.

Moving Day Tips

Pack Strategically

Load large furniture first, then fill gaps with boxes. Use every inch efficiently.

Dismantle Furniture

Take apart beds, tables, and wardrobes. Store components vertically against walls.

Protect Belongings

Use dust sheets and proper packing materials. Storage units can be dusty environments.

Long-term vs Short-term Storage

Temporary Storage

House moves often need temporary storage. Choose convenience over cost savings for short periods.

Long-term Storage

Extended storage justifies investing in proper organisation and slightly larger units for easier access.

Vehicle Transportation

Transit Van Hire

Perfect for 35 sq ft worth of belongings. Ideal for studio flats or one-bedroom properties with minimal furniture.

Luton Van Hire

Necessary for 75 sq ft worth of items. Standard choice for a two-bedroom house move.

Multiple Trips

Sometimes multiple carloads work better than van hire. Factor in your time and effort.

Final Size Selection

Start Conservative

Select the smallest size that comfortably accommodates your belongings. You can always upgrade.

Consider Convenience

Slightly larger units often provide significantly more convenience for minimal extra cost.

Plan for Change

Your needs might evolve. Choose facilities offering flexible sizing options.

Find Storage Units in Major UK Cities

Ready to find the perfect storage unit? We’ve partnered with top facilities across the UK’s major cities to help you find the right size unit at competitive prices.

Storage in Major Cities

• London Self Storage: From compact 25 sq ft units in central London to larger 200 sq ft spaces in outer zones, find competitive storage options across the capital.
• Birmingham Self Storage: Birmingham offers excellent value storage with sizes from garden shed units to warehouse spaces for business storage needs.
• Manchester Self Storage: Compare storage facilities across Greater Manchester, with options suitable for student storage, house moves, and business requirements.
• Liverpool Self Storage: Find affordable storage units near Liverpool, from small 35 sq ft units to large vehicle storage spaces.
• Bristol Self Storage: Explore storage options in Bristol and its surrounding areas, featuring facilities with a range of unit sizes and flexible rental terms.

Each city offers different pricing and availability, so compare options to find the best value for your chosen unit size.

Getting Help

Contact storage facilities directly for personalised advice. Experienced staff can often recommend optimal sizes tailored to your specific requirements.

Most facilities offer flexible rental terms and the option to change sizes, so your initial choice doesn’t lock you in permanently.

Remember: the proper storage unit size strikes a balance between cost, convenience, and capacity. Take time to assess your needs properly – it’s worth getting right from the start.