Concrete Calculator
Volume and bags for slabs and bases.
Gravel Calculator
Tonnes and bulk bags by area and depth.
MOT Type 1
Sub-base material for driveways and paths.
Paving Blocks
Number of blocks or slabs needed.
Area Calculator
Area and perimeter from length × width.
Cubic Converter
Convert m³, ft³, yd³ and litres.
Free construction calculators
Planning a driveway, patio, slab, or path? These free construction calculators help you estimate exactly how much material to order — concrete, gravel, sub-base, and paving — so you avoid both shortfalls and expensive over-ordering. Each tool works in metric or imperial units and adds a sensible waste allowance.
Build it up in layers
A durable hard surface is built in layers. Start by measuring the area, lay a compacted MOT Type 1 sub-base, then finish with concrete, paving, or gravel. Getting the sub-base right is what stops a surface sinking or cracking later.
Order a little extra
Materials settle, spill, and get cut to fit, so it is always wise to order 5–10% more than the bare calculation. These tools include a waste allowance, but check ground conditions and confirm final quantities with your supplier.