Bar Bending Schedule Format in Excel — Free BBS Template
A bar bending schedule is the cutting and bending list for every reinforcement bar on a project — mark, diameter, shape, cutting length, count, and weight. The steel supplier cuts from it, the bar bender bends from it, and the contractor procures against the weight summary at the bottom of it. It is the most arithmetic-heavy document on a site and the one where a single wrong cutting length multiplies across four hundred bars.
This template computes weight for you. Enter diameter and the sheet applies d²/162 to get unit weight in kg/m, multiplies through the bar count and cutting length, and rolls the result into a summary of total steel by diameter — which is the number you actually place an order against.
Bend deduction reference
| Bend / hook | Deduction / length |
|---|---|
| 45° bend | 1d |
| 90° bend | 2d |
| 135° bend | 3d |
| 135° hook length | 10d (min. 75mm) |
| 90° hook length | 12d |
Cutting length is not the same as the length shown on the drawing. Steel stretches at a bend, so the flat length before bending is shorter than the sum of the bent legs. Skipping the deduction over-orders steel on every single line.
Worked example — one beam
Take a 300mm × 450mm beam, 4.0m clear span, 25mm cover: 4 bars of 16mm at the bottom, 2 bars of 12mm at the top, and 8mm stirrups with 135° hooks at 150mm centres. Each main bar is anchored 300mm into each support — a round illustrative bearing allowance; your actual development length depends on concrete and steel grade — so cutting length = 4000 + 2×300 = 4600mm for both the 16mm and 12mm bars.
| Bar | Cutting length | Nos | Total length | Unit wt (kg/m) | Total wt (kg) |
|---|---|---|---|---|---|
| Bottom, 16mm | 4.60 m | 4 | 18.40 m | 1.580 | 29.08 |
| Top, 12mm | 4.60 m | 2 | 9.20 m | 0.889 | 8.18 |
| Stirrups, 8mm | 1.36 m | 27 | 36.72 m | 0.395 | 14.51 |
| Total steel, this beam | 51.76 | ||||
The stirrup's 1.36m cutting length already includes both 135° hooks and the three 90° corner deductions — the same closed-rectangle convention this site's column tie ground-truth case is built on, just at this beam's dimensions. 27 stirrups come from 4000mm ÷ 150mm centres, plus one for the first bar in the run. Unit weight is d²/162 for each diameter — 16mm at 1.580 kg/m, 12mm at 0.889 kg/m, 8mm at 0.395 kg/m — multiplied straight through to a 51.76kg total for this one beam.
Common mistakes
Using the drawing length as the cutting length. The most common BBS error by a wide margin, and it inflates a steel order by two to four percent across a project.
Forgetting hook allowance on stirrups. Stirrups have two 135° hooks. At 10d each on an 8mm bar that's 160mm of hook length alone (subject to a 75mm-per-hook floor on small diameters), and a slab has thousands of them.
Ignoring lap length. Bars longer than the standard 12m stock length need laps, and laps consume steel that never appears on the drawing.
Wrong unit weight. d²/162 gives kg per metre. Using a rounded table value instead of the formula introduces drift that compounds across the schedule.
No summary by diameter. A total weight figure is useless for procurement. You order 8mm and 16mm separately, so the schedule has to break down that way.
What each column means
| Column | What goes in it |
|---|---|
| Member | Footing, column, beam, slab, staircase, lintel. Group rows by member so the bender can work section by section. |
| Bar Mark | The reference mark from the structural drawing. Keep it identical to the drawing — the bender matches on this. |
| Dia (mm) | 8, 10, 12, 16, 20, 25, 32. Drives the weight formula. |
| Shape Code | The bend shape reference. Straight, L-bend, U-bar, cranked, stirrup. |
| No. of Members | How many identical members, e.g. 12 identical columns. |
| Bars per Member | Bars of this mark in one member. |
| Total Nos | Auto-calculated. Members × bars per member. |
| Cutting Length (m) | Clear length + hooks + development length − bend deductions. See the deduction reference sheet. |
| Total Length (m) | Auto-calculated. |
| Unit Weight (kg/m) | Auto-calculated as d²/162. |
| Total Weight (kg) | Auto-calculated. |
A bar bending schedule feeds into the steel line of a full estimate. Pair it with the BOQ format in Excel to price the rest of the job.
Frequently asked questions
What is the formula for unit weight of steel?
d²/162, where d is the bar diameter in mm, giving weight in kg per metre. A 12mm bar is 144/162 = 0.888 kg/m.
What is cutting length in a bar bending schedule?
The flat length of the bar before bending — clear span plus hooks and development length, minus bend deductions.
How do you calculate bend deduction?
1d for a 45° bend, 2d for 90°, 3d for a 135° hook, where d is the bar diameter.
Does this BBS template calculate weight automatically?
Yes. Enter diameter, cutting length, and bar count, and the sheet computes unit weight, total length, total weight, and a summary by diameter.
Can I use this format for slab, beam, and column reinforcement?
Yes — the Member column groups rows by element, and the same schedule covers footings, columns, beams, slabs, staircases, and lintels.