QuickBOQ LogoQuickBOQ Pro

Bar Bending Schedule

Enter a member and its reinforcement. Cutting lengths, bar counts and steel weight are worked out as you type — and every bar shows how its figure was reached.

Beam

3 bar groups defined

Dimensions & Clear Cover

Concrete Vol: 0.81 m³

Reinforcement Bars (3)

BAR0 mm
A
Straight (IS 2502 Code 00)
BAR0 mm
A
Straight (IS 2502 Code 00)
BAR0 mm
WD
Rectangular stirrup (IS 2502 Code 33)

Total steel

0.00 kg

0.00 quintal

Members

1

1 in total

Concrete Volume

0.81 m³

Bar groups

3

Rows

0

8 errors

No Reinforcement Scheduled Yet

Add members and specify bar dimensions on the left. The full schedule with cutting lengths and weights will calculate instantly here.

8 things need fixing

  • B1 — Bar diameter must be greater than 0.
  • B1 — A is required for a straight.
  • B1 — Bar diameter must be greater than 0.
  • B1 — A is required for a straight.
  • B1 — Bar diameter must be greater than 0.
  • B1 — W is required for a rectangular stirrup.
  • B1 — D is required for a rectangular stirrup.
  • B1 — Number of bars must be greater than 0.

Free to browse. Log in to unlock the full Rate Analysis of every Civil and Electrical item in the latest CPWD DSR — and download them free.

See what QuickBOQ Pro includes

Complete Engineering Guide to Bar Bending Schedules (IS 2502 & IS 456)

1. Cutting Length & Bend Deductions (IS 2502 Table II)

When a steel rebar is bent, outer curve fibers stretch and elongate. If bend deductions are omitted, fabricated cages will exceed the member's concrete boundary or violate nominal cover requirements:

  • 45° Bend: Deduct 1 × Bar Diameter (1d)
  • 90° Bend: Deduct 2 × Bar Diameter (2d)
  • 135° Bend: Deduct 3 × Bar Diameter (3d)

2. Stirrup Hook Allowances (IS 13920 & IS 2502)

In ductile earthquake-resistant detailing (IS 13920 Clause 6.3.2), all transverse ties and stirrups must terminate in 135° standard hooks with an extension beyond the bend of at least 10d, but never less than 75 mm. Standard anchor hooks require 16d per IS 2502 Table I.

3. Unit Weight Formula (D²/162.28)

The standard derivation from steel density (7,850 kg/m³) yields:
Unit Weight (kg/m) = D² / 162.28

Where D is the nominal diameter in millimeters. In CPWD DSR (Item 5.22), rebar is billed per quintal (100 kg) or metric tonne (1,000 kg).

4. 1D Stock Cut Optimization (12m Rods)

Steel reinforcement in India is delivered in standard 12-meter commercial stock lengths. QuickBOQ solves the 1D Bin Packing Cutting Stock problem to determine optimal nesting combinations, preventing off-cut scrap from exceeding standard 3% to 5% tender margins.

Frequently asked questions

What is a Bar Bending Schedule (BBS)?

+
A Bar Bending Schedule (BBS) is an organized list of reinforcement bars for an RCC structure. It details the bar mark, diameter, shape description, cutting length, number of bars per member, total bar count, and total weight in kilograms or quintals. It is essential for site fabrication, quantity takeoff, and tender billing.

What are the standard bend deductions in IS 2502?

+
During bending, rebar elongates at the outer curve. To ensure accurate fabrication, IS 2502 Table II specifies standard deductions from total perimeter: deduct 1 × diameter (1d) for a 45° bend, 2 × diameter (2d) for a 90° bend, and 3 × diameter (3d) for a 135° bend.

What is the hook allowance for 135° seismic stirrups under IS 13920?

+
Per IS 13920 Clause 6.3.2 and IS 2502 Table I, stirrups and links must have a 135° bend with an extension beyond the bend of at least 10 × bar diameter (10d), but not less than 75 mm. This guarantees confinement under seismic forces.

How is development length (Ld) calculated per IS 456?

+
Per IS 456:2000 Clause 26.2.1, development length Ld = (ϕ × σs) / (4 × τbd), where ϕ is bar diameter, σs is design stress (0.87 fy), and τbd is design bond stress. For deformed TMT bars (Fe 500) in M25 concrete, standard tension lap is 49d. In compression (Clause 26.2.1.1), τbd increases by 25%, resulting in 39d.

What is the standard unit weight formula for rebar?

+
The unit weight of round reinforcement bars is calculated as D² / 162.28 kg/m, where D is bar diameter in millimeters. Standard unit weights: 8 mm = 0.395 kg/m, 10 mm = 0.617 kg/m, 12 mm = 0.888 kg/m, 16 mm = 1.578 kg/m, 20 mm = 2.466 kg/m, 25 mm = 3.853 kg/m, 32 mm = 6.313 kg/m.

How does 1D Stock Cut Optimization work in QuickBOQ BBS?

+
Commercial TMT steel bars in India are supplied in standard 12-meter lengths. QuickBOQ includes a 1D Bin Packing Cutting Stock algorithm that computes optimal cut patterns to minimize off-cut scrap, keeping wastage within standard 3% to 5% tender limits.

More free CPWD tools and references

Steel Weight Calculator

Bar-by-bar reinforcement weight and rod count, with the D²/162 chart.
Weigh steel

Concrete Mix Estimator

Cement, sand and aggregate for M10 to M25, with the dry-volume working.
Estimate a mix

Brick & Block Estimator

Brick count and mortar volume for any wall, net of openings.
Count bricks

Construction Cost Calculator

Preliminary build cost by area, floors, city and finish, with a component breakup.
Cost a building

Cement Consumption Coefficients

Cement per unit of work for 444 CPWD DSR items, in kg and bags.
Open the table

CPWD DSR Civil 2023

Every chapter, item, unit and rate in the official schedule.
Browse the DSR