Construction Calculators
Concrete volume and gravel for slabs, pads, and footings — formula on each tool page.
2 calculators
Related guides
How Much Does a Concrete Patio Cost?
A breakdown of what drives concrete patio pricing — materials, labor, finish, and the factors that push an estimate up or down.
GuideHow Much Gravel Do You Need for a Driveway?
Convert length, width, and depth into tonnes or cubic yards, plus a practical waste allowance for compaction and uneven ground.
GuideHow Much Mulch Do You Need for Garden Beds?
A clear method for bed area, depth, bags versus bulk delivery, and when to refresh an existing mulch layer.
GuideHow to Estimate Decking Boards and Framing Basics
Turn deck length and width into board count with gap spacing, and know what the board calculator does not include.
GuidePatio vs Driveway Concrete Thickness
Why patio, shed, and driveway slabs use different thicknesses — and how thickness multiplies your concrete volume.
GuideHow to Compare Contractor Quotes Side by Side
Line up materials vs labour, allowances, and exclusions — use your own quantity checks against lump sums.
GuideWhy Patio Bases Need Gravel Before Concrete
How sub-base depth affects stability and how to estimate gravel and concrete as two separate material lines.
GuideUS and UK Units on the Same Project
Feet vs metres, gallons vs litres — keep one system per calculation so orders don’t go wrong.