Rebar Spacing Calculator | Free Construction Calculators

Calculate optimal rebar spacing and quantity based on application and load requirements.

feet
feet

Rebar Spacing by Application

  • 24 inches: Light duty (patios, sidewalks, light residential)
  • 18 inches: Standard residential slabs (most common)
  • 12 inches: Heavy duty (driveways, garages, commercial slabs)
  • 6-8 inches: Industrial or special load requirements

Building Code Requirements

Building codes typically require:

  • Maximum spacing: 18 inches on center for residential
  • Minimum 3 inches of concrete cover over rebar
  • Rebar must be positioned in lower third of slab thickness
  • Use chairs or dobies to maintain proper height
  • Overlap splices must meet minimum lap length requirements

Grid Pattern

Rebar should form a grid pattern with bars running both lengthwise and widthwise at the specified spacing. Tie bars together at intersections with rebar tie wire.