CONSTRUCT MATH

#6 Rebar Calculator — 3/4 Inch Heavy Bar

Estimate #6 (3/4-inch) rebar bar count and weight for heavy footings, structural columns, and reinforced concrete walls. Returns lineal feet and total weight.

01

Enter Dimensions

ft
ft
%

Add 10% for standard cuts and overlaps

02

Results

Bars Needed

38bars

Total Lineal Feet

608lin ft

Total rebar length including waste

Total Weight

406lb

#4 rebar weight per CRSI

Slab Area

240sq ft

Editorial Standards

Each calculator is reviewed for formula accuracy, unit consistency, and alignment with current U.S. building practices before publication. We verify outputs against published engineering references and real-world project data. Learn more about our methodology.

#6 rebar (3/4 inch diameter) is the heavy-duty reinforcement for structural elements requiring high steel area: large footings beneath load-bearing CMU walls, reinforced concrete walls 8+ ft tall, structural columns, and commercial slabs. At ~2× the cost and 2× the weight of #4, only specify it when engineering or code requires the extra capacity.

For more typical residential applications, use the #4 or #5 calculator.

How to Estimate #6 Rebar

3/4 inch diameter · 1.502 lb per LF · 30 inch Class B lap · for heavy footings, columns, and engineered work.

Bars = ⌈Dimension ÷ Spacing⌉ + 1. Weight = LF × 1.502 lb/ft.

#6 Rebar Quick Reference

  • Diameter: 3/4 inch (0.75 in)
  • Weight: 1.502 lb/ft (30.04 lb per 20 ft stick)
  • Steel area: 0.44 sq in
  • Min bend dia: 4.5 in
  • Class B lap splice: 30 in
  • Cost: ~$1.00-1.50/LF (2025)
  • Stock: 20 ft or 40 ft sticks (40 ft preferred for fewer splices)
  • Common use: heavy footings, structural columns, tall reinforced walls

Frequently Asked Questions

01

When do I need #6 rebar?

#6 rebar (3/4 inch diameter) is specified for: heavy footings (30 inch+ wide), reinforced concrete walls 8+ ft tall, structural columns, commercial slabs supporting vehicle loads, and engineered residential beams.

02

How much does #6 rebar weigh?

1.502 lb per linear foot — over 2× the weight of #4 (0.668 lb/ft). A 20 ft stick weighs 30 lb; a 40 ft stick weighs 60 lb. Plan handling accordingly.

03

How much does #6 rebar cost?

$1.00-1.50 per LF in 2025 — about 2× the cost of #4 by foot. A 20 ft stick: $20-30. By the ton: $900-1,300.

04

Is #6 rebar handled by hand?

Yes, but two people are recommended for any piece over 10 ft long. A 20 ft #6 stick at 30 lb is awkward to maneuver alone; tying it in place definitely takes two.

05

Can #6 rebar replace 2 layers of #4?

Roughly equivalent in steel area: 1 × #6 (0.44 sq in) ≈ 2 × #4 (2 × 0.20 = 0.40 sq in). Specifying #6 reduces piece count and placement labor, but each piece is harder to handle. Usually trades 50% fewer placements for ~2× material cost per pound.

Looking for the general calculator?

Calculate rebar quantity, spacing, and total weight for concrete slabs, footings, and walls. Covers #3 through #8 bar sizes using CRSI published weight tables.

Open the Rebar Calculator: Bar Count & Weight →

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