Free Rebar Layout Spacing Calculator
Calculate the number of rebar pieces and actual spacing for a slab or wall of known dimensions.
ft
ft
in
in
Bars Along Length
12
Bars Along Width20
Total Bars (both directions)32
Bars Along Length vs Slab/Wall Length
Rebar Layout
Bars in One Direction = floor((Dimension - 2 x Offset) / Spacing) + 1
Rebar is placed in a grid pattern with bars running in both directions. The edge offset (typically 2 to 3 inches) keeps rebar away from the form edges for adequate concrete cover.
Example Calculation
20 x 12 ft slab, 12-inch spacing, 3-inch edge offset.
- 01Net length = 240 - 6 = 234 in
- 02Net width = 144 - 6 = 138 in
- 03Bars along length = floor(138/12) + 1 = 12
- 04Bars along width = floor(234/12) + 1 = 20
- 05Total = 12 + 20 = 32 bars
Frequently Asked Questions
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