Concrete & Construction Calculators
Free, practical tools for concrete and construction planning — estimate concrete volume and bags, work out a mix ratio, count rebar, blocks, and bricks, and price a slab before you pour.
Concrete Volume Calculator
Estimate the concrete volume of a slab, footing, or column in cubic feet, cubic yards, and cubic metres from its dimensions, with a 10% waste allowance for ordering
Concrete Bag Calculator
Work out how many 40, 60, or 80 lb bags of pre-mixed concrete you need for a given volume, including a 5% waste allowance and rounded up to whole bags
Concrete Mix Ratio Calculator
Break a concrete volume into cement, sand, and aggregate quantities for any mix ratio, applying a dry-volume factor and converting cement into bags
Rebar Calculator
Estimate the number of reinforcing bars and total bar length for a two-way slab mat from the slab dimensions, bar spacing, and edge clearance
Block & Brick Calculator
Estimate how many concrete blocks or bricks a wall needs from its length and height, using the unit face area including mortar plus a wastage allowance
Slab Cost Calculator
Estimate the cost of a concrete slab from its dimensions and unit prices for ready-mix concrete, labor, and formwork, broken down and totalled
Concrete Curing Time Calculator
Work out when the pour is ready to walk on, to strip forms, and to load, from the cement type and the average curing temperature