Size is the single most important decision when buying a storage shed. Get it wrong and you will either outgrow the shed within a year or waste money on space you never use. Here is a practical method to calculate exactly what you need.
The Floor Space Method
List every item you plan to store, then estimate the floor space each requires:
- Push mower: 12-15 sq ft
- Riding mower: 25-35 sq ft
- Wheelbarrow: 6-8 sq ft
- Bike: 6-8 sq ft
- Trash/recycling bins: 8-10 sq ft
- Garden tools (rack): 2-4 sq ft
- Shelving unit: 6-10 sq ft
- Workbench: 12-16 sq ft
Add up your items, then add 30% for walkway space and future growth. That total is your minimum shed size.
Common Shed Sizes and What They Hold
4x6 ft (24 sq ft) — Tool Storage
Fits: hand tools, small garden supplies, a few shelves of seasonal items. Best for homeowners with minimal storage needs or who already have a garage.
6x4 ft (24 sq ft) — Compact Garden Shed
Similar capacity to 4x6 but with a different orientation. Fits a push mower vertically plus wall-mounted tools.
7x5 ft (35 sq ft) — Small Shed
Fits: push mower, garden tools, trash bins, and a shelving unit. Good for small yards where space is at a premium.
7x7 ft (49 sq ft) — Medium Shed
Fits: push mower, wheelbarrow, garden tools, bike, shelving, and some seasonal storage. The most popular size for suburban homes.
8x6 ft (48 sq ft) — Medium-Large Shed
Fits: similar to 7x7 but with wider doors for easier equipment access. Good for riding mowers in tight yards.
10x8 ft (80 sq ft) — Large Shed
Fits: riding mower, all garden tools, multiple shelving units, workbench, and seasonal storage. Approaching workshop territory.
10x12 ft (120 sq ft) — Workshop Shed
Fits: full workshop setup, riding mower, extensive tool storage, and still has room to work inside. May require a building permit in some areas.
12x20+ ft (240+ sq ft) — Large Equipment Storage
Fits: ATVs, small tractors, extensive workshop, or serves as a detached studio. Almost certainly requires a permit.
Height Matters Too
Interior height determines what you can store vertically. Standard shed heights range from 6 to 8 feet. If you plan to hang items from the ceiling or store tall equipment, look for extra-tall models. A 7-foot interior height is comfortable for most adults to stand in.
The Future-Proofing Rule
Whatever size you calculate, consider going one size up. Most shed owners accumulate more items over time. A shed that feels spacious today will feel cramped in three years if you buy new equipment, take up new hobbies, or need to store kids' seasonal gear.
Don't Forget the Foundation
Your foundation must match the shed size exactly. A shed that is 8x6 ft needs a foundation that is at least 8x6 ft. Building a foundation slightly larger than the shed is fine and actually recommended for stability.
Still not sure? Call us at (619) 304-4620 with your storage list and we will recommend the right size.
