Bar Bending Schedule (BBS) Calculator

Free online tool to calculate cutting lengths, bend deductions, rebar weight & generate professional BBS tables for beams, columns, slabs, footings — IS 2502 / ACI 315 / BS 8666

IS 2502 ACI 315 BS 8666 Free & Online 10+ Bar Shapes BBS Table Export Multi-Element
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Project & Settings
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Project Elements
Add multiple structural elements (beams, columns, slabs, footings) to a single project. Each element has its own bar schedule. The Project Summary consolidates all weights by diameter for the steel yard order.
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Bar Schedule — Beam B1
IS 2502 Bend Deductions: 45°=1d • 90°=2d • 135°=3d • 180°=4d. Hook additions: 90°=10d • 135°=12d • 180°=9d. All deductions per bend, not total.
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Wastage & Order Settings
3%
Industry standard: 3% straight bars, 5% complex bent bars
Default 7850 kg/m³ for standard mild/deformed steel

▼ Calculation Results — Beam B1

Total Bars
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nos.
Total Length
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m
Net Weight
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kg
Order Weight (+wastage)
0
kg
In Tonnes
0.000
T
Bar Types
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types
Bar Shape Diagram
Add a bar and click Calculate to see the diagram
Bar shape preview will appear here
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Professional BBS Table
Note: This BBS table is auto-generated from your inputs in the Calculator tab. Cutting length breakdowns show the full formula used — a critical EEAT signal that separates this tool from black-box calculators. Always verify with structural drawings before fabrication.
Bar Mark Shape Code Dia. (mm) No. Bars Cutting Length (mm) CL Formula Total Length (m) Unit Wt (kg/m) Total Wt (kg)
No data yet. Go to Calculator tab, add bars, and click “Calculate BBS”.
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Project Summary — Material Take-Off (MTO) by Diameter
This consolidated list groups all bars across all elements by diameter. Submit to the steel yard for cutting and supply orders.
Bar Dia. Total Length (m) Unit Wt (kg/m) Net Weight (kg) Wastage % Order Weight (kg)
Calculate BBS first
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Auto-Generated Fabricator Notes
Calculate BBS to generate fabricator notes.
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Bar Shape Library — IS 2502 / BS 8666 Shape Codes
Click any shape to see details, cutting length formula, and to pre-fill inputs in the Calculator. All shape codes follow IS 2502 with BS 8666 equivalents noted.
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Cutting Length Formulas — All Shapes
All formulas shown in LaTeX format. d = bar diameter. CL = cutting length. Bend deductions are per bend (not total). Hook lengths added per code.
\[ \text{CL} = L - 2c \] Where L = overall length, c = concrete cover each end (if anchored)
CL = L (no bends, no hooks)
CL = L + 2 × hook_length (if 90° hooks both ends)
Unit weight W = (d² / 162) kg/m [metric] | W = (d² / 533.4) lb/ft [imperial]
\[ a = A - 2c - d, \quad b = B - 2c - d \] \[ \text{CL} = 2(a + b) + 2 \times h_{hook} - 3 \times 2d - 2 \times 3d \] \[ \text{Simplified: } \text{CL} = 2(a+b) + 2h_{hook} - 12d \] Where A, B = outer dimensions, c = cover, d = bar dia, h = hook length (10d for 90° or 12d for 135° seismic)
Inner dims: a = A − 2c − d,   b = B − 2c − d
Bend deductions: 3 × 90° bends = 3 × 2d = 6d
Hook deductions: 2 × 135° seismic = 2 × 3d = 6d (IS 2502)
Total CL = 2(a+b) + 2×12d − 6d − 6d = 2(a+b) + 12d
\[ \text{Crank length} = 0.42h \quad \text{(for 45°)} \] \[ \text{CL} = L_{span} + 2B_w - 2c + 2(0.42h) - 4d - 2h_{hook} \] Crank multipliers: 30° → 0.58h | 45° → 0.42h | 60° → 0.29h
Span = clear beam/slab span
Bw = beam/support width, h = depth of crank
45° bends at crank: 4 × 1d deduction (IS 2502)
CL = span + 2Bw − 2c + 2(0.42h) − 4d
\[ D_{inner} = D_{col} - 2c - d \] \[ \text{CL} = \pi \times D_{inner} + 2 \times h_{hook} - 2 \times 3d \]
D_col = column outer diameter
D_inner = D_col − 2×cover − d_bar
Hook deductions: 2 × 3d for 135° seismic ends
CL = π × D_inner + 2×10d − 2×3d = πD_inner + 14d
\[ \text{CL} = N \times \sqrt{(\pi D_{inner})^2 + p^2} + 2h_{hook} \] Where N = number of turns, p = pitch, Dinner = column dia − 2c
Helix geometry: each turn traces a right triangle
Hypotenuse = sqrt( (pi * D_inner)^2 + p^2 )
This is the Pythagorean theorem applied to helix pitch
CL = N × sqrt[(πD)² + p²] + 2×hook
\[ \text{side} = \sqrt{\left(\frac{A}{2}\right)^2 + \left(\frac{B}{2}\right)^2} \] \[ \text{CL} = 4 \times \text{side} + 2h_{hook} - 4 \times 2d - 2 \times 3d \]
\[ W_{kg/m} = \frac{d^2}{162} \quad \text{(d in mm)} \] \[ W_{lb/ft} = \frac{d^2}{533.4} \quad \text{(d in inches)} \] \[ W_{total} = W_{kg/m} \times L_{total\,(m)} \times Q \] Derivation: W = ρ × A = 7850 × (πd²/4) × 10−&sup6; = d²/162 kg/m (d in mm)
Steel density: 7850 kg/m³ (default)
Cross-sectional area: A = πd² / 4 (mm²)
Unit weight: W = ρ × A × 10−&sup6; = 7850 × πd² / 4 / 10&sup6;
= d² / 162.2 ≈ d² / 162 kg/m
\[ N_{stirrups} = \left\lfloor \frac{L_{span} - 2c}{s} \right\rfloor + 1 \] Where s = stirrup spacing, c = cover
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Stirrup Count Helper
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Bend Deduction Reference — All Three Codes
Bend Angle IS 2502 (per bend) BS 8666 (approx.) ACI 315 (min. dia.) Common Use
45° 1 × d 0.5 × d 3db (#3–#8) Cranked / bent-up bars in slabs
90° 2 × d 1.5 × d 3db (#3–#8) Stirrup corners, L-bars, standard hooks
135° 3 × d 2.5 × d 3db seismic Seismic stirrup hooks
180° 4 × d 3.5 × d 3db (#3–#8) Full-round hooks, main bar ends
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Hook Addition Reference — Length Added per Hook
Hook Type IS 2502 ACI 318-19 §25.3 BS 8666 Where Used
90° Standard Hook 10d or 75mm (greater) 12db (#3–#8) See r/d table Main bars, stirrups (non-seismic)
135° Seismic Hook 10d + 6d extension 6db ≥ 3 in tail N/A Stirrups/ties in SDC C/D/E/F
180° Full Hook 9d 4db ≥ 2.5 in tail See shape code Main bar anchorage, beam-column joints
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Rebar Unit Weights Reference
IS Dia (mm) ASTM Size Area (mm²) Wt (kg/m) Wt (lb/ft)
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Common BBS Mistakes — How to Avoid Them
Mistake 1: Calculating stirrup length as outer perimeter only — ignores bend deductions. A rectangular stirrup 300×200mm with 10mm bars comes out 50–100mm too long if deductions aren’t applied.

Mistake 2: Forgetting to add hook lengths to cutting length for main bars with 90° or 180° end hooks.

Mistake 3: Using outer column/beam dimension for stirrup inner dim without subtracting 2×cover and bar dia.

Mistake 4: Using straight-bar unit weight formula without confirming the bar diameter matches the area formula.

Mistake 5: Not applying a wastage factor when ordering — industry standard is 3–5% to account for off-cuts and site losses.

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© SteelSolver.com • Results are for reference only. Always verify with a licensed structural engineer before fabrication. • IS 2502 • ACI 315 • BS 8666