Steel & Reinforcement Calculators
Reinforcing steel is what gives concrete its tensile strength, and estimating it is a layout exercise: how many bars each way, how much overlap at the splices, and how many stock lengths that adds up to. The Rebar Calculator takes a slab or footing area, the bar spacing and the edge cover, and returns the bar count in each direction, the total lineal feet including lap splices, the number of 20-foot sticks to buy, and the grid-intersection count for tie wire. It counts a single flat mat — one layer of steel. The bar size, spacing, cover and lap length must come from the structural drawings for anything load-bearing; the calculator does the take-off, not the design. Chair supports, edge dowels, corner bars and any second (top) mat are separate.
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All Steel & Reinforcement Calculators · 1
Rebar Calculator
Rebar quantity, spacing and lineal feet for a slab or footing grid.
Steel & Reinforcement Guides
How to Calculate Rebar Quantity for Concrete
Rebar quantity comes from the reinforcement design — bar spacing and grid size — not from the concrete volume it reinforces.
How to Calculate Concrete for Footings
A footing is calculated the same way as a slab — length × width × depth — but often needs to be split into multiple sections for a stepped or T-shaped profile.