RHCES Bar Bending Schedule (BBS) Generator

Inputs

Add Mark

Bar size (mm)

Length A (mm)

Length B

Length C

Hooks (90/180)

No. of Bars

Cutting length rules

Total cut length = ΣA + ΣB + ΣC + hook allowance − bend deductions.
90° hooks (2 ends): bend deduction = 2·d per bend (4·d total). 180° hooks (2 ends): hook allowance = +9·d per hook (18·d total), with the same 2·d per-bend deduction still applied.
Steel weight (kg/m) = d²/162. Total weight = qty × cut length × d²/162.

Mark	Size	A	B	C	Hooks	Qty	L (mm)	Wt (kg)

Results

Total bars—

Total length—

Total weight—

By size — qty—

By size — weight—

Export

About this calculator

This tool builds a bar bending schedule (BBS) — the cut length, unit weight, and total weight of straight or hooked reinforcing bars — following standard rebar-detailing practice used on RC drawings, with a CSV export for takeoff. It's built for detailers, estimators, and site engineers preparing steel schedules and material orders.

Method & formulas

Each row's cut length is the sum of its straight segment lengths, adjusted for bends and hooks:

Cut length = ΣA + ΣB + ΣC + hook allowance − bend deduction 90° bend at each end: bend deduction = 2 × 2d = 4d total 180° hook at each end: hook allowance = 2 × 9d = 18d total, plus the same 4d bend deduction

Weight uses the standard rebar mass approximation (density ≈ 7850 kg/m³, circular section):

Unit weight w = d² / 162 (kg/m, d in mm) Bar weight = quantity × cut length (m) × d² / 162

Worked example

Mark S1 — a 10 mm stirrup-type bar with legs A=200 mm, B=200 mm, C=100 mm, 180° hooks at both ends, quantity 20:

Segment sum = 200 + 200 + 100 = 500 mm Hook allowance = 18 × 10 = 180 mm Bend deduction = 4 × 10 = 40 mm Cut length = 500 + 180 − 40 = 640 mm = 0.64 m Unit weight = 10² / 162 = 0.617 kg/m Weight per bar = 0.64 × 0.617 ≈ 0.395 kg Total for 20 bars ≈ 7.90 kg

Assumptions & limitations

Uses a simplified, single bend-deduction/hook-allowance rule (2d per 90° bend, 9d per 180° hook) — some detailing standards specify slightly different values by diameter or bend angle, so confirm against your project's own BBS convention.

The d²/162 weight formula assumes standard reinforcing-steel density; verify for stainless, epoxy-coated, or other non-standard bar types.

Does not check minimum bend diameters, bar spacing, or lap/development length — use it alongside the Development & Splice Length tool for those checks.

Totals don't include a wastage/offcut allowance — add your project's standard percentage before ordering material.

Verify results against the governing code and a licensed engineer's judgment before issuing for construction or procurement.

FAQ

Q: Where does the d²/162 weight formula come from?

A: It's the standard approximation for the mass per meter of deformed steel reinforcing bar, derived from the bar's nominal circular cross-section and steel's density — used almost universally in rebar-detailing practice.

Q: Why does a 180° hook both add and remove length?

A: The straight leg lengths you enter (A/B/C) run along the bar centerline to each bend point; the hook allowance adds the curved hook itself, while the bend deduction corrects for the fact that bending compresses the outer fiber relative to a simple sum of straight segments — a standard detailing correction, not double-counting.

Q: Can I export the schedule for procurement?

A: Yes — "Download CSV" exports mark, size, segment dimensions, hook type, quantity, cut length, and weight for every row currently in the table.

InputsReset