About Rebar Scheduling & Detailing Calculator
The rebar scheduling calculator produces a bar bending schedule with cutting lengths, weights, and bend deductions per BS 8666, ACI SP-66, and AS 3600. It is used by detailers and contractors to quantify reinforcement, order steel, and check shapes before fabrication.
Add bar rows with a mark, shape code, bar size, quantity, and the dimensioning parameters A, B, and C. The tool applies the shape-code cutting-length formula with the correct bend deductions, returns the cutting and total lengths, the weight per bar and total weight, and a weight summary grouped by bar diameter, all in real time.
How It Works
- Select a BS 8666 shape code for each bar and enter its dimensional parameters in millimetres.
- Compute the minimum bend radius from the bar diameter (2d up to T16, 3.5d at T20, 4d to T32, 7d at T40) and the resulting bend deductions.
- Apply the shape-code formula to get the cutting length, for example L = A + B - (0.5r + d) for a single 90-degree bend.
- Multiply the cutting length by the standard mass per metre for the bar size and the quantity, then total the weights and group them by diameter.
Worked Example
A T12 bar to shape code 11 (one 90-degree bend) with A = 2000 mm and B = 500 mm has a minimum bend radius r = 2 * 12 = 24 mm and a deduction of 0.5 * 24 + 12 = 24 mm, so the cutting length is 2000 + 500 - 24 = 2476 mm. At 0.888 kg/m that is 2.199 kg per bar, or 8.796 kg for a quantity of 4.
Formulas
- Minimum bend radius
r = m * d- Bend deduction (single 90-degree)
deduction = 0.5 * r + d- Cutting length (shape code 11)
L = A + B - (0.5 * r + d)- Bar weight
weight = mass_per_metre * (L / 1000) * quantity
Standards & References
- BS 8666:2020
- ACI SP-66
- AS 3600
Frequently Asked Questions
Which reinforcement detailing standards are supported?
The schedule follows BS 8666:2020 for scheduling, dimensioning, bending and cutting of steel reinforcement, with ACI SP-66 and AS 3600 also selectable. Shape codes and bend allowances follow the BS 8666 tables.
How is the bar weight per metre determined?
The tool uses the standard nominal mass per metre for each bar size, for example 0.617 kg/m for T10, 0.888 kg/m for T12, and 2.466 kg/m for T20, then multiplies by the cutting length and quantity.
What is a bend deduction and why does it matter?
A bend deduction accounts for the steel that is consumed around a bend radius, so the true cutting length is the sum of the leg dimensions minus the deductions. Ignoring it would over-order steel and produce bars that are too long.
Which shape codes does the calculator handle?
It supports common BS 8666 shape codes including 00 (straight), 11 and 33 (single bend), 14 (U-bar), 21 (cranked), 31/38 (double bend), 44 (links/stirrups), 51 (S-hook), and 99 (special), each with its own cutting-length formula.