Patio Size & Paving Calculator
Planning a new patio means knowing how many slabs to order and roughly what the materials will cost before you commit — get it wrong and you're either short on slabs mid-build or left with an expensive pile of leftovers. Enter your patio's length and width along with your chosen slab size below, and we'll calculate the number of slabs needed, with a sensible allowance for cutting, plus a rough UK cost range so you can budget with confidence.
Enter your patio dimensions
We'll work out how many slabs you need, plus a cutting allowance.
Enter a length and width above to see how many slabs you'll need.
Recommended for your patio
Garden furniture to make the most of your new outdoor space.
£799.00
Pros
- All-weather PE rattan weave
- Rising table with built-in ice bucket
- Showerproof, UKFR-compliant cushions
Cons
- Heavy — needs two people to move
- Premium price for the corner + footstools configuration
£219.99
Pros
- Compact — fits small patios and balconies
- Removable, machine-washable cushion covers
- Glass-top coffee table with storage shelf
Cons
- Cushions fade after a season in direct sun
£89.99
Pros
- Fully weatherproof resin, rattan-effect weave
- Built-in storage table doubles as a coffee table
- Compact size ideal for balconies
Cons
- Seats two only
- No cushions included as standard
Frequently asked questions
Do I need planning permission for a patio?
Most garden patios count as permitted development and don’t need planning permission, provided the patio (combined with any other hard surfacing) doesn’t take the total covered area of the garden over 50%. If your patio will raise the ground level significantly, sit close to a boundary, or your property has restrictive covenants or is a listed building, it’s worth checking with your local council first.
How thick should patio slabs be?
For a standard domestic patio taking foot traffic and garden furniture, 35-40mm concrete slabs are typical. If the patio will need to support a driveway, hot tub, or heavier loads, look for thicker slabs (50mm+) or ones specifically rated for vehicular use.
What base do I need under paving?
A typical patio build is a compacted sub-base of MOT Type 1 hardcore (75-100mm), topped with a bed of sharp sand and cement mortar (or a semi-dry mortar mix) that the slabs are laid on. Good drainage and a slight fall away from the house (roughly 1:80) are essential to stop water pooling or running into your home.
How much extra should I order for cutting and wastage?
We build in a 10% allowance on top of the raw number of slabs needed to cover your patio area, which typically covers cuts around edges, borders, and any breakages during laying. Irregular patio shapes or intricate patterns may need a slightly higher allowance.