Rebar Spacing Calculator
Calculate rebar spacing, bars per foot, and steel ratio for concrete slabs. Checks ACI code compliance for maximum spacing.
Inputs
ACI 318: one-way slab minimum L/20 (simple) to L/28 (one end continuous); 4–8" typical
ACI 318 Table 20.6.1.3: slabs not exposed 1.5"; footings in soil 3"; exposed to weather 2"
Results
Bar Spacing
7.74 in
ACI Code Compliant
1
How to Use This Calculator
- Enter slab thickness (inches) and select rebar size (#3 through #10).
- Set required steel area (in²/ft) from your structural design.
- Review maximum allowable spacing (inches) and actual provided steel area.
- Spacing must not exceed 3× the slab thickness or 18 inches per ACI 318.
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