Rebar Calculator for Concrete Construction
Rebar Calculation Results
Total Linear Feet: ft
Number of Bars:
Including Waste: ft
Total Cost: $
Error
How to Calculate Rebar Needed for Concrete Slabs
Our free rebar calculator helps contractors, engineers, and DIY enthusiasts accurately estimate rebar requirements for concrete projects:
- Accurate estimation for both lengthwise and widthwise rebar placement
- Customizable spacing between bars (standard is 12 inches)
- Supports all standard rebar sizes from #3 (3/8") to #8 (1")
- Accounts for material waste (default 10% but adjustable)
- Optional cost calculation when unit price is provided
Rebar Calculation Formula:
((Length ÷ Spacing) × Width) + ((Width ÷ Spacing) × Length) = Total Linear Feet
This formula ensures proper reinforcement for your concrete slab by calculating rebar needed in both directions.