Reinforcement & Structural Calculators
Explore our suite of free reinforcement & structural calculators to precisely estimate volume, weight, and costs for your next project. Select a tool below to get started.
Rebar Calculator
Estimate rebar bars, linear footage, weight, and cost for slabs, footings, and walls.
Wire Mesh Calculator
Estimate welded wire fabric rolls, sheets, weight, and cost for concrete slabs, driveways, sidewalks, and industrial floors.
Rebar Weight Calculator
Convert rebar linear footage to weight in lbs, tons, and kg, or reverse from a tonnage spec to footage — for procurement, logistics, and cost planning.
Rebar Spacing Calculator
Calculate rebar bar count from a target c-t-c spacing or find spacing from a bar count, with ACI 318-19 compliance checks for slabs, footings, walls, and beams.
Estimating Rebar and Wire Mesh
Concrete has immense compressive strength but very weak tensile strength. Reinforcement (rebar and welded wire mesh) bridges cracks and ties slabs together so they do not separate. Estimating involves determining the spacing grid, overlap requirements (lap splices), and boundary clearances.
Core Formula
Total Linear Feet = (Runs across length + Runs across width) × Required Length + (Splice overlaps)
Frequently Asked Questions
- What does the rebar number mean? (e.g. #4 rebar)
- In the US, the rebar number represents the diameter in 1/8 inch increments. So #4 rebar is 4/8 inch (1/2 inch) in diameter. #3 is 3/8 inch, etc.
- What is standard rebar spacing for a slab?
- For residential flatwork, #3 or #4 rebar is commonly tied in a grid spacing of 18 inches to 24 inches on center.
- What is a lap splice?
- Rebar bars are sold in 10-foot or 20-foot lengths. To create a continuous piece, two bars must be overlapped and tied together. Code dictates lap lengths typically ranging from 20 to 40 times the bar diameter.
- Is wire mesh better than rebar?
- Wire mesh is excellent for preventing wide surface cracks in light-load slabs. However, rebar provides far superior structural and load-bearing strength. Wire mesh is cheaper and faster to install.