UK Construction Calculators
Free building calculators for UK homeowners, DIYers and tradespeople. Choose your project below, enter measurements in metres or feet, and receive quantities you can order confidently.
Brick, block and mortar calculators
Everything required for a wall, from the first course to the final bag of sand. All three tools share the same mortar method, so their figures always agree.
Concrete, paving and driveway calculators
Footings, patios, sub-bases and driveways. Calculate cubic metres, tonnes, slabs, bulk bags and ready-mix deliveries before contacting the merchant.
Cubic metres, bags, cement and ballast for slabs and footings.
Slabs, block paving, sub-base, bedding mortar and patio fall.
MOT Type 1 tonnes, bulk bags, layers and dig-out depth.
Sharp, building and kiln-dried sand, plus sand and cement mixes.
MOT Type 1, ballast, sand and gravel in tonnes and bulk bags.
Tonnage, coverage and driveway cost per m².
Tile, grout, adhesive and paint calculators
Floors, walls and decorating. Count tiles and boxes, then the adhesive, grout and paint that accompany them.
Tiles per m², boxes and wastage for floors and walls.
Adhesive per m² and 20 kg bags by trowel notch.
Grout per m² from tile size, joint width and depth.
Litres and tins for rooms, walls, ceilings and exteriors.
Stair calculator
Rise, going, pitch and stringer length, checked against Approved Document K for UK homes.
One project, several calculations
Picture this. You are planning a garden wall. You need the bricks, the mortar and a concrete footing underneath. Each figure normally lives on a different website, with different assumptions.
One site assumes American brick sizes. Another ignores the mortar joint completely. The totals never quite match, so you round everything up and pay for the difference.
Our approach: every calculator here uses identical UK sizes and 10 mm joints. Material densities match across every tool too, so the numbers stay consistent.
Which construction calculator do I need?
Most building projects need two or three calculators. Here is the sequence we would recommend.
| Project | Calculators to use | What you get |
|---|---|---|
| Garden wall | Concrete, then brick, then mortar | Footing volume, brick count, cement and sand |
| House extension | Concrete, block, brick, mortar | Foundations, inner leaf, outer leaf and mortar |
| Patio or path | Paving | Slabs, MOT Type 1, bedding mortar and jointing |
| Sand and cement for any job | Sand | Sharp, building or kiln-dried sand, plus cement bags |
| Shed base | Sub-base, then concrete | MOT Type 1 tonnes and dig depth, then the slab |
| Tarmac driveway | Sub-base, then tarmac | MOT Type 1 tonnes, then asphalt tonnes and cost |
| Bathroom or kitchen tiling | Tile, adhesive, grout | Tiles and boxes, adhesive bags, grout bags |
| Decorating a room | Paint | Litres and the cheapest tin mix |
| Repointing old brickwork | Mortar | Lime or cement mortar by joint depth |
| Loft conversion stairs | Stair | Rise, going, pitch and headroom checks |
Always begin with whatever goes in first. Footings and sub-bases always come before walls and surfaces.
Building a wall yourself? Our step-by-step brick wall guide covers setting out, laying and pointing. For the concrete underneath, read our garden wall footing guide.
What makes our construction calculators different?
Many calculators online come from the United States. They assume cinder blocks, cubic yards and 80 lb bags. Ours follow UK practice from the start.
- UK sizes and units. Standard 215 × 102.5 × 65 mm bricks, 440 × 215 mm blocks and metric measurements, with feet as an option.
- UK products. 25 kg cement bags, bulk bags of sand and aggregate, and tins sold by British retailers.
- UK guidance. Mortar designations, Approved Document K for stairs and British Standards where they apply.
- Real prices. We check merchant and DIY store listings regularly, and every price table shows its date.
- Shareable results. Download or share any estimate as an image for your builder or merchant.
We believe a calculator should show its working. That is why every page explains its formula and includes worked examples you can check by hand.
How we build and test each calculator
We start with the method a UK builder or merchant would use. Then we compare the results against manufacturer data sheets and manual calculations.
Before any update goes live, we rerun the worked examples and check old and new versions side by side. Every calculator works on phones, needs no sign-up and costs nothing.
Looking for advice rather than numbers? Browse our building guides. Every guide links back to the calculator that fits it.
Construction calculator FAQs
Plan the whole job in one place
Remember that garden wall with three websites and three different answers? Here, the footing, bricks and mortar all come from one consistent method. Last reviewed: October 2026.
Which calculator should we build next? Patio, plaster and scaffolding tools are already on our list. Tell us what you need through our contact page.