A rebar takeoff means reading every reinforcement label in a drawing and moving the quantity, diameter and length into a list. Done by hand it takes hours, and it is easy to count a bar twice or miss one entirely. This guide explains the logic of a rebar schedule and how to automate it in AutoCAD.
What is a bar bending schedule (BBS)?
A bar bending schedule lists every bar in the project with its position (mark) number, diameter, quantity, length and total weight. Ordering, cutting and bending on site are based on it, and so are cost estimates and progress payments.
How is rebar weight calculated?
The weight per metre of a bar is approximately d² / 162 (d = diameter in mm, result in kg/m). Standard unit weights (TS 708):
| Diameter | kg/m |
|---|---|
| Ø8 | 0.395 |
| Ø10 | 0.617 |
| Ø12 | 0.888 |
| Ø14 | 1.208 |
| Ø16 | 1.578 |
| Ø20 | 2.466 |
Total weight = quantity × length (m) × unit weight. For 10Ø12 L=600: 10 × 6.00 × 0.888 = 53.28 kg.
Reading rebar labels in a drawing
Rebar is usually annotated like this:
10Ø12 L=600– 10 bars, 12 mm diameter, 600 cm long15Ø14/20– 15 bars of Ø14 at 20 cm spacingL=200-300orL=200~300– variable length (the average length is used)
Depending on the font, the diameter symbol may appear as Ø, %%c, f or Q. Misreading these symbols and variable lengths is the most common source of errors in manual takeoffs.
Automated rebar takeoff in AutoCAD with RebarPro
RebarPro is a free AutoCAD LISP add-in that automates the whole process:
FAQ
Does it work on AutoCAD LT? No. LISP add-ins need the full version of AutoCAD on Windows.
Is it paid? RebarPro is currently free to download. An internet connection is required for the initial license check.
Should I still review the results? Yes. Automation saves hours, but always review quantities before ordering or invoicing.