Rebar Weight Calculator

Slab Reinforcement

Typical slab uses #3 or #4 bars at 12-18 inch spacing. Calculate bars per direction. Add top and bottom mats for two-way reinforcement. Include lap splices of 40 bar diameters.

Beam Reinforcement

Bottom bars carry tension. Top bars resist negative moments. Stirrups provide shear resistance. Typical beam uses #6-#8 main bars with #3-#4 stirrups at 6-12 inch spacing.

Column Reinforcement

Vertical bars carry axial load. Ties confine concrete and prevent buckling. Typical column uses 4-8 vertical bars (#6-#10) with ties at 12-16 inch spacing.

Footing Reinforcement

Bottom mat resists bending from soil pressure. Use #4-#6 bars at 8-12 inch spacing. Add top mat for large footings. Include dowels for column connections.

Example 1: Slab Reinforcement

Slab: 20 ft × 30 ft
#4 bars at 12 inch spacing
Bars needed: 60 bars × 30 ft + 30 bars × 20 ft = 2,400 ft
Weight: 2,400 × 0.668 = 1,603 lb (727 kg)

Example 2: Column Reinforcement

Column: 12 ft height, 8 columns
8 × #8 bars per column
Total bar length: 8 × 8 × 12 = 768 ft
Weight: 768 × 2.670 = 2,051 lb (930 kg)

Example 3: Beam Reinforcement

Beam: 24 ft length, 4 beams
4 × #7 bottom bars + 2 × #6 top bars
Bottom: 4 × 4 × 24 × 2.044 = 785 lb
Top: 2 × 4 × 24 × 1.502 = 288 lb
Total: 1,073 lb (487 kg)