About These Calculators

This site offers two free, browser-based tools for preparing bar bending schedules (BBS): a calculator for the British Standard for the scheduling, dimensioning, bending and cutting of steel reinforcement — BS 8666:2020 — and a calculator for the Indian Standard equivalent — IS 2502. Both are built for site engineers, reinforcement detailers, quantity surveyors and students who need an accurate cutting length and steel weight without working through the standard's tables by hand. Most of the detail below describes the BS 8666:2020 calculator; the IS 2502 calculator follows the same approach against its own standard's shape codes and tables.

What it does

• Calculates the cutting length of a bar for any of the 37 standard BS 8666:2020 shape codes, using the length formulas from Table 5.
• Applies the correct minimum scheduling radii, mandrel diameters and hook allowances from Table 2, based on the bar diameter you select.
• Computes steel weight per bar and per bar mark using nominal mass per metre, and produces a diameter-wise weight summary for the whole schedule.
• Lets you save multiple projects, add your company details and logo, and export a formatted schedule to Excel, PDF or CSV — with the shape diagrams embedded.

How the numbers are calculated

Cutting lengths follow BS 8666:2020 Table 5, where the length of the bar is measured along its centre line. Each shape's formula subtracts a bend allowance — a function of the bar diameter and the minimum bend radius — from the sum of the overall dimensions you enter. The bend radii, mandrel sizes and hook allowances come from Table 2 of the same standard.

Steel weight is based on nominal mass per metre (consistent with BS 4449), derived from the bar's cross-sectional area and the density of steel. These are the same nominal figures used across the industry for scheduling and take-off.

What it does not do

The tool is a scheduling aid, not a design tool. In particular:

• It does not add lap or anchorage lengths automatically — those are a structural design matter governed by Eurocode 2 (BS EN 1992-1-1) and your project specification.
• It does not deduct concrete cover for you — enter dimensions already net of cover if that's how your drawing is dimensioned.
• It does not add cutting wastage — apply your own project allowance for procurement quantities.

This tool assists with scheduling only. It is not a substitute for a checked, engineer-approved bending schedule. Always verify against approved structural drawings before fabrication.

Privacy in short

Everything runs in your browser. Your project data is stored locally on your own device, not uploaded to any server. See the privacy policy for the full detail.