Rebar takeoff from the schedules and the details.
Rebar lives in slab and footing schedules, wall elevations, typical details and general notes. Good rebar takeoff software turns those into pieces, lengths and weights. The estimator still has to catch what's implied: laps, hooks, dowels, corner bars, and the bars a typical detail says to repeat everywhere.
- Schedules and details
- Hooks and laps
- Weights to tons
- Tools compared
Read these sources
- Foundation and slab schedules: bar size, spacing, direction, top and bottom mats.
- Wall and pier schedules and elevations: verticals, horizontals, ties, dowels into footings.
- Typical details: corner bars, bars at openings, slab edge and thickened edge bars, construction joint dowels.
- Structural general notes: lap lengths or lap schedule, cover, grade (ASTM A615 or A706), coating, mechanical splices.
- Beam and column schedules: longitudinal bars, stirrups and ties with spacing zones.
Reinforcing quantities
| Item | Source | Often missed? |
|---|---|---|
| Slab and mat bars | Schedules, plans | Top bars over supports |
| Footing and wall bars | Schedules, typical details | Dowels and corner bars |
| Ties and stirrups | Beam and column schedules | Spacing zones near supports |
| Bars at openings | Typical details | Yes, if not drawn per opening |
| Accessories | Specs, CRSI practice | Chairs, bolsters, standees |
| Mechanical splices | General notes, details | Couplers priced each |
Lengths that add up
- Standard hooks (ACI 318): a 90° hook adds an extension of 12 bar diameters; a 180° hook adds 4 bar diameters but not less than 2-1/2 in; plus the bend itself. Ties and stirrups have their own hook rules.
- Laps: lap lengths depend on bar size, concrete strength, cover, spacing and position (top bars need longer laps). Use the lap schedule in the general notes. A flat percentage is a placeholder.
- Stock lengths: bars commonly come in 20, 40 and 60 ft lengths; long runs need laps at stock length intervals unless the spec requires couplers.
ASTM A615 to tons
Nominal weights in lb/ft: #3 0.376, #4 0.668, #5 1.043, #6 1.502, #7 2.044, #8 2.670, #9 3.400, #10 4.303, #11 5.313.
Illustrative wall example.
Verticals: (80 × 12 ÷ 12) + 1 = 81 per face × 2 = 162 bars × (12 ft + 2.0 ft lap to dowel) = 2,268 lf
Horizontals: (12 × 12 ÷ 12) + 1 = 13 per face × 2 = 26 bars × 80 ft = 2,080 lf
+ laps at 40 ft stock: 1 lap per bar × 26 × 1.6 ft (from lap schedule) = 42 lf
Dowels to footing: 162 × 4 ft (incl. hook) = 648 lf of #5
Weight: #5 (2,268 + 648) × 1.043 = 3,041 lb; #4 (2,122) × 0.668 = 1,418 lb
Total ≈ 4,459 lb ≈ 2.23 tons (before corner bars and opening bars)
Lap and hook lengths in the example are placeholders. Use the project's schedule.
Price separately
- Epoxy-coated (ASTM A775 or A934): higher material cost, coated accessories and touch-up; handling is slower.
- Galvanized (ASTM A767): fabricated before or after galvanizing per spec.
- Low-alloy weldable (ASTM A706): often required in seismic frames or where welding is specified.
- Stainless and GFRP: specialty pricing and lead times.
How rebar software differs
| Type | Examples | Best at |
|---|---|---|
| Rebar estimating and fabrication suites | aSa Estimating (Applied Systems Associates) | Takeoff by structure with automatic hooks and laps, pieces, lengths and weights; pricing set up by you; integration with fabrication modules |
| CAD-based detailing | RebarCAD (AutoCAD-based) | Bar schedules and placing drawings |
| 3D BIM detailing | Tekla Structures | Modeled rebar with schedules from the model; heavy for estimating only |
| General PDF takeoff | Bluebeam, PlanSwift | Measuring runs and areas; no bar logic |
| AI-assisted takeoff | Several newer products | Proposed quantities from drawings for review |
The question to ask any vendor: how does it handle typical details that apply to every opening or corner, and lap schedules that vary by bar size?
Where any takeoff needs a person
- Implied quantities: bars a typical detail applies everywhere but nobody drew.
- Degraded scans: faded or low-resolution sheets lose bar marks and spacing callouts.
- Conflicts between schedules and sections.
- Verbal changes not on the documents.
Run one bid side by side.
Pick a real job
Choose a recent bid with the plan set, legend, schedules and at least one addendum.
Build a baseline
Have an estimator check the quantities you want to test.
Run it side by side
Run the same set through your current tool and through a RenderDraw sample.
Score misses and review time
Record missed items, wrong inclusions and the time spent correcting each result.
Your sample files remain private while we assess the request. There is no obligation to proceed.
Questions estimators ask.
What is rebar takeoff software?
Software that turns structural drawings into reinforcing quantities: bar sizes, pieces, lengths, hooks, laps and weights, often with pricing and fabrication links.
How much does #5 rebar weigh?
1.043 lb per foot under ASTM A615 nominal values.
How long is a standard hook?
Under ACI 318, a 90° standard hook extends 12 bar diameters and a 180° hook extends 4 bar diameters, but not less than 2-1/2 inches, beyond the bend.
Can AI do rebar takeoff?
AI can propose quantities from schedules and plans. Laps, hooks, dowels and bars implied by typical details need estimator review.
How do I convert rebar to tons?
Multiply linear feet by the nominal weight per foot for each bar size, sum the pounds, and divide by 2,000.
Can I test RenderDraw on my drawings?
Yes. Send one representative plan set for a free sample takeoff at renderdraw.com/trial. RenderDraw proposes quantities with the source sheet on each row for your estimator to review.
Send one plan set. Judge the result yourself.
A focused, no-obligation evaluation on your own drawings. Your sample files remain private while we assess the request.
- Upload one representative plan set (a legible PDF set is the most reliable starting point), plus an addendum if you have one.
- RenderDraw reviews the set and the scope you want tested.
- We follow up with what was extracted, what was flagged for review, and the most useful next step.
Where these numbers come from
We checked this guide against the standards, manufacturer documents and industry references below (last reviewed November 2026). Figures marked as rules of thumb are typical ranges, not requirements; your project documents, local code and your own cost history govern.