Rebar Calculator — Fast Takeoffs for Slabs, Footings & Walls
Use this free Rebar Calculator to estimate the number of bars, total linear footage, and steel weight for common concrete elements. Choose Slab, Footing, or Wall, enter your dimensions, spacing, cover, and bar size, and get instant totals in both imperial and metric units. This tool is designed for quick takeoffs — always verify structural requirements with local codes or a licensed engineer.
What It Calculates
- Bar count in each direction/layer
- Total length by bar group and overall
- Total weight in pounds and kilograms
Quick Tips
- Edge offsets start the first bar in from the edge for better cover and spacing.
- Cover is the distance from concrete surface to the steel — common values: slabs 2″ bottom, footings 3″, walls 2″.
- For simple takeoffs, add a small waste allowance (e.g., 5–10%) for cuts and overlaps.
Related Tools
Planning concrete volume as well? Try our Concrete Slab Calculator and Gravel Calculator.
Disclaimer
This tool provides takeoff estimates only and is not a design tool. Reinforcement selection, spacing, laps, development, and detailing must follow applicable codes and a licensed engineer’s direction.
Important Estimate Disclaimer
The results provided by this calculator are intended as general estimates only and should not be considered precise engineering measurements. Actual material requirements, costs, and quantities can vary significantly based on site conditions, local building codes, soil type, reinforcement requirements, climate exposure, and the intended use of your project.
These calculators are designed to help you plan and budget your project more effectively, but they do not replace professional advice from a qualified contractor, engineer, or building inspector. Always verify your calculations and assumptions with trained professionals before placing material orders or commencing construction.
For more information on the assumptions, formulas, and data used in these tools, see our Data Sources and Methodology pages.
Material estimates, cost figures, and volume calculations are approximate and may not reflect your actual requirements. Always double-check dimensions and project-specific needs, and consider adding a contingency allowance for waste, over-excavation, and unforeseen conditions.
If you are unsure about any aspect of your project — including structural requirements, reinforcement needs, drainage, or load-bearing capacity — consult with a licensed professional before proceeding.