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Rebar Material Calculator
Updated Aug 25, 2026 Reviewed Aug 25, 2026
Estimate two-way rebar grids, stock bars, laps, waste, nominal weight and optional cost across multiple areas.
Two-way reinforcement takeoff
Enter areas, approved spacing, bar sizes and stock details
Result
Calculation summary
Enter values to see the result
Your result, breakdown, assumptions, and warnings will appear here.
Grid preview
Two-direction reinforcement layout
Bars along length
13
Bars across width
21
Stock pieces before waste
34
How to use this calculator
- 1Add each rectangular reinforcement area and enter quantity, dimensions, edge offset and layers.
- 2Enter the approved maximum spacing and bar size for each direction.
- 3Set stock length, project-specified lap length, waste and output units.
- 4Optionally enter a current price per unit of nominal steel weight.
Formula
Bars across = ceil(usable width ÷ spacing) + 1
Lines are split into whole stock pieces; each split adds the entered lap and each size is rounded after waste.
Calculation steps
- Convert geometry and subtract bar-center edge offsets.
- Count both grid directions for every quantity and layer.
- Split long lines into stock pieces and count laps.
- Aggregate by size, apply waste and calculate nominal weight.
- Apply the optional price basis.
Worked example
A 4 m × 3 m grid at 1 m spacing with no offset uses four bars along the length and five across the width before waste.
Assumptions
- This is not structural design.
- Offset is measured to the bar centerline.
- Offcuts, bends, hooks, chairs and ties are excluded.
- Nominal unit mass should be confirmed with the supplier.
- Costs exclude fabrication, labor, delivery and tax.
Sources
Frequently asked questions
Does it choose rebar size or spacing?
No. Both must come from the approved design.
Does edge offset equal concrete cover?
Not necessarily; this input is measured to the bar centerline.
Are laps included?
Yes, using the entered length without approving it.
Are offcuts reused?
No. Each continuous line is rounded independently.
Can each direction use a different bar size?
Yes. Longitudinal and transverse sizes are selected independently.
Does cost include labor or fabrication?
No. It applies only the entered price to nominal purchased steel weight.
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