#3 Rebar Calculator — 3/8 Inch Bar Count & Weight
Estimate #3 (3/8-inch) rebar bar count and weight for ties, stirrups, light slabs, and decorative concrete work. Based on ASTM A615 standard grades.
Enter Dimensions
Add 10% for standard cuts and overlaps
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.
#3 rebar (3/8 inch diameter) is the lightweight workhorse for secondary reinforcement: column ties, beam stirrups, lightweight decorative slabs, and corner ties between perpendicular layers of larger bars. At 0.376 lb per LF, it's the lightest and cheapest rebar size and the easiest to bend by hand.
For primary slab reinforcement, step up to #4 Rebar Calculator. For column ties paired with vertical bars, see the Column Rebar Calculator.
How to Estimate #3 Rebar
Total LF = Pieces × Length. Weight = LF × 0.376 lb/ft.
#3 Rebar Quick Reference
- Diameter: 3/8 inch (0.375 in)
- Weight: 0.376 lb/ft (7.52 lb per 20 ft stick)
- Steel area: 0.11 sq in
- Min bend dia: 2.25 in
- Class B lap splice: 15 in
- Cost: ~$0.30-0.50/LF (2025)
- Primary use: ties, stirrups, light decorative slabs
Frequently Asked Questions
What is #3 rebar used for?
#3 rebar (3/8 inch diameter) is used for: ties around vertical column bars, stirrups in beams, light decorative slabs, garden walls, and tying corners in horizontal-laid bars. Too small for primary slab reinforcement in most applications.
How much does #3 rebar weigh?
0.376 lb per linear foot. A 20 ft stick weighs 7.5 lb — the lightest standard rebar size and easiest to work with by hand.
Can I use #3 rebar in a residential slab?
Only for very light loads (small patios, walkways, garden pads). Most residential slabs require #4 (1/2 inch) minimum for adequate steel area. Verify with ACI 318 shrinkage/temperature steel requirements.
How much does #3 rebar cost?
$0.30-$0.50 per LF — the cheapest standard rebar size. A 20 ft stick: $6-10. Bulk pricing similar to other sizes at ~$700/ton.
What is the bend radius of #3 rebar?
Minimum 90° hook inside diameter is 6 × bar diameter = 2.25 inches for #3. Standard hook length: 12 × bar diameter = 4.5 inches. #3 is easier to bend by hand than larger sizes.
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 →