#3 Rebar (3/8")
Weight: 0.376 lb/ft
Use: Light duty, slabs, driveways
Lap splice: 15" (40d)
#4 Rebar (1/2")
Weight: 0.668 lb/ft
Use: Residential, footings, walls
Lap splice: 20" (40d)
#5 Rebar (5/8")
Weight: 1.043 lb/ft
Use: Commercial, foundations
Lap splice: 25" (40d)
#6 Rebar (3/4")
Weight: 1.502 lb/ft
Use: Heavy, columns, beams
Lap splice: 34" (45d)
Steel prices fluctuate, but here are current 2026 market rates for USA construction:
❓ Frequently Asked Questions About Rebar (2026)
How much rebar do I need for my slab?
For a standard 20'×20' slab with #4 rebar at 18" spacing, you'll need approximately 1,200 linear feet of rebar (about 800 lbs or 0.4 tons). The calculator accounts for both directions and includes waste factor. Enter your dimensions above for exact quantities.
What's the standard rebar spacing for a concrete slab?
For residential slabs, #4 rebar at 12-18 inches is typical. For heavier commercial slabs, #5 at 12 inches. Always check local building codes - our calculator automatically adjusts to minimum spacing requirements based on ACI 318-26 building codes.
How much does rebar cost in 2026?
Current 2026 prices range from $850-1,250 per ton depending on size: #3: $850-950/ton, #4: $900-1,000/ton, #5: $950-1,050/ton, #6: $1,000-1,100/ton. Use our calculator with current prices for accurate estimates.
How do you calculate rebar weight?
Rebar weight is calculated using ASTM A615 standard weights: #3 (0.376 lb/ft), #4 (0.668 lb/ft), #5 (1.043 lb/ft), #6 (1.502 lb/ft), #7 (2.044 lb/ft), #8 (2.670 lb/ft). Our calculator automatically applies these standards.
What size rebar do I need for a footing?
For residential footings, #4 rebar (1/2") is typically sufficient. For heavier loads or commercial projects, #5 (5/8") or #6 (3/4") may be required. Always consult your structural engineer for final specifications.
How much overlap for rebar splices?
Lap splice length is typically 40-50 times the bar diameter. For #4 rebar (1/2"), that's 20" (40×0.5"). For #5 rebar (5/8"), that's 25" (40×0.625). Our calculator includes lap splices when you check that option, adding approximately 10-15% to your total.
How much rebar do I need for a 20x20 slab?
A 20'×20' slab with #4 rebar at 18" spacing requires approximately 1,200 linear feet of rebar, weighing about 800 lbs (0.4 tons). With current prices of $950/ton, material cost would be around $400 plus tie wire.