Garden Shed Size Calculator
Choosing the right shed size means balancing what you need to store — mowers, bikes, tools, or a full workshop setup — against your garden space and UK permitted development limits, which generally cap outbuildings at 2.5m in height near boundaries without planning permission. Get the size wrong and you either waste garden space or end up with a shed you can't move around in. Tell us what you're storing below and we'll suggest a floor area and matching standard shed sizes, plus a few well-reviewed sheds to get you started, keeping in mind most builds still need a solid, level base.
What do you need to store?
Tick everything that applies — we'll estimate the floor area you need.
Select at least one item above to see your recommended shed size.
Recommended sheds
A few well-reviewed options to match the size you've calculated.
- Resin
- Small gardens
- 6x6ft
£429.00
Pros
- Weatherproof, UV-protected resin construction
- No rot, rust or peeling paint
- Lockable double doors with skylight for natural light
Cons
- Needs a solid, level base for assembly
£349.00
Pros
- Traditional overlap timber cladding
- Budget-friendly for the size
- Includes windows for natural light
Cons
- Requires annual timber treatment
- Metal
- Small gardens
- 4x6ft
£249.99
Pros
- Rust-proof galvanised steel construction
- Window and 2 vents for light and airflow
- Lockable door for added security
Cons
- Requires a level base for installation
Frequently asked questions
Do I need planning permission for a shed this size?
In most UK gardens, sheds fall under permitted development and don’t need planning permission provided they cover no more than 50% of the garden, sit behind the front of the house, and are no taller than 2.5m within 2m of a boundary (up to 4m dual-pitch roof elsewhere). Larger workshop-sized buildings or sheds near a boundary may still need a check with your local council.
What base do I need for my shed?
Small sheds (up to around 6x4ft) are usually fine on paving slabs or a timber frame base. Anything from 8x6ft upwards, or sheds housing heavier items like a workshop, benefits from a proper concrete or concrete-and-slab base to keep the floor level and prevent damp and movement over time.
How much extra space should I allow beyond my stored items?
We add a 30% buffer on top of the raw footprint of your items to account for walking space, opening doors, and reaching things at the back — sheds packed edge-to-edge with no access space are much harder to actually use.
Is it better to size up if I am unsure?
Generally yes. Sheds are cheap relative to the cost of running out of space later, and buying one size up gives you room for future purchases like a second bike or a mower upgrade without needing a new shed in a couple of years.