Cutting lengths and steel weights for bar bending schedules per IS 2502:1963 — stirrups, seismic stirrups (IS 13920), hooked bars — with the method stated for every result.
Cutting length per bar
mm
order length mm (next whole 25, Cl 5.1.1)
Method:
Unit weight: ز/162 kg/m — the nominal mass basis (7850 kg/m³ steel). Actual delivered weight varies with rolling tolerance; our rolling margin calculator covers that check.
Stirrups: IS 2502 Table VIII gives the rectangular stirrup cutting length directly as 2(A+E) + 24d from the scheduled external dimensions. For ductile-detailing zones, IS 13920 Cl 8.1(b) requires 135° hooks with a straight extension of 10d (≥ 75 mm) — the seismic option adds 2 × max(10d, 75) to the stirrup body, the standard site convention for that case.
Hooks and bends: IS 2502 Table II adds an allowance to scheduled dimensions per hook (H = 9d / 11d / 13d / 17d for steel factor k = 2 / 3 / 4 / 6) and per bend (B = 5d – 7d), each rounded to 5 mm with a 75 mm minimum. IS 2502 Cl 3.8 separately requires the straight portion beyond a stirrup's end curve to be at least 8d.
Verified against the IS 2502:1963 BIS PDF — see our verified constants table.
Most BBS tutorials tell you to deduct 2d per 90° bend and 3d per 135° bend. That shortcut belongs to the centerline-measurement convention — you measure leg lengths along the bar's centreline and subtract the bend geometry. It is not in IS 2502. The code instead works from scheduled external dimensions and adds Table II allowances. Both conventions produce sensible numbers; they just must not be mixed. This calculator uses the IS 2502 method for code shapes and says so on every result card.
Given: column stirrup for a 300×450 member with 40 mm cover → A = 220, E = 370 (external), Ø8, 25 nos.
IS 2502 Table VIII: cutting = 2(220+370) + 24×8 = 1180 + 192 = 1372 mm → order 1375 mm
Weight = 0.395 kg/m × 1.372 m = 0.54 kg per bar → 13.5 kg for 25 stirrups
Seismic variant: 2(590) + 2×80 = 1340 mm (135° hooks, 10Ø = 80 ≥ 75 mm extensions)
Under the popular centerline convention: 2d. Under IS 2502's allowance method: there is no deduction — you add Table II allowances to external dimensions instead. Pick one convention per schedule and stay with it; this tool uses IS 2502.
135° hooks with a 10d (≥75 mm) straight extension into the confined core (IS 13920). A 90° hook straightens when cover spalls in an earthquake — exactly when the stirrup must hold.
Mass = π/4 × Ø² × 7850 kg/m³ = 0.00617 ز ≈ ز/162. It is the nominal cross-section value; rolling tolerance means delivered weight differs — which is what the rolling margin check is for.
Often used together with this calculator — pick the next step in your design or QA loop.
Deep dive: read the full significance guide — the code clauses, assumptions and site meaning behind these numbers.