Concrete and mortar
Calculators
- Groundworks
Ballast calculator
Example: Order: 15 × cement bags and 2.31 t of ballast
Concrete calculator
Example: Order: 114 bags
Concrete mix calculator
Example: Order: 13 × cement bags, 0.70 t sharp sand and 1.41 t gravel
Mortar calculator
Example: Order: 3 bags of cement and 0.30 t of sand
- Decking and fencing
Postcrete calculator
Example: Order: 27 bags of post-fix (3 per post if you mix whole bags per hole: 30)
- Brickwork
Sand and cement calculator
Example: Order: 5 × cement bags and 0.51 t of sand (4:1 sand to cement (1:4 cement to sand))
Screed calculator
Example: Order: 21 × cement bags and 2.27 t of sharp sand
- Flooring
Self-levelling compound calculator
Example: Order: 3 bags of levelling compound (48.0 kg)
Screed drying time calculator
Example: About 90 days before testing for floor finishes
Project estimators
Garden room estimator
Plan a garden room: base, stud walls, insulation to a U-value, flat roof and a supply check. Costs only from your own prices.
Garden wall estimator
Plan a garden wall: footing concrete, bricks or blocks, mortar and wall ties, in one printable shopping list.
Shed base estimator
Plan a shed base from dig to finish: muck away, MOT Type 1, concrete or slabs and ballast, in one printable shopping list.
Start here
Start with how to measure a concrete slab.
Start here: guides
How to measure a concrete slab
Measure length, width and depth, keep mm and m apart, then choose bags or ready-mix. How much extra to allow for waste.
How much concrete for fence posts?
Hole size from the post maker, post-fix vs mixed concrete, and how many bags to buy for a row of fence posts.
Mortar mix ratios explained
What a mortar ratio like 1:4 or 1:5 means, where the right ratio is specified, wet vs dry volume, and when pre-mixed bags make sense.
Working safely with cement
Cement can burn skin and eyes and cutting dust harms lungs. What HSE guidance says about gloves, eye protection and dust.