Bar Bending Schedule Calculator
Home & ConstructionCutting lengths, laps and weights for every bar mark, with the working shown and CSV export.
Runs entirely in your browser — nothing is uploaded
A bar bending schedule is the document that goes to the bar bender, and its arithmetic is what gets disputed on site. The subtlety is that the two allowances pull opposite ways: a hook is extra steel beyond the leg so it is added, while a bend follows a shorter path than the corner it turns so it is deducted. Every row here shows its own working, so a figure can be traced rather than argued over.
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Features
- Five bar shapes — straight, L-bend, U-bend, stirrup and hooked.
- Hook allowances and bend deductions per IS 2502, both adjustable.
- Laps added automatically where a bar exceeds the 12 m stock length.
- Working shown for every row: straight length, hooks added, bends deducted.
- Summary by diameter, which is how steel is actually ordered.
- CSV export for a spreadsheet or the bar bender.
- Runs entirely in your browser — nothing is uploaded.
How to use the Bar Bending Schedule Calculator
- 1Add a row for each bar mark on the drawing.
- 2Pick the shape and enter its leg dimensions.
- 3Set the diameter and how many of that mark there are.
- 4Read the cutting lengths, then export the schedule.
Frequently asked questions
How is cutting length calculated?
Add the straight legs, add the hooks, then subtract the bend deductions. A hook is steel beyond the end of the leg so it lengthens the bar; a bend cuts the corner so the bar is shorter than the sum of its legs. Per IS 2502 the standard allowances are a 9d hook, and deductions of 1d at 45°, 2d at 90° and 3d at 135°.
What is the cutting length of a rectangular stirrup?
2 × (a + b) + 2 hooks − bend deductions, where a and b are the centre-line dimensions. A stirrup has three 90° corners and two 135° hooks, so with 9d hooks it gains 18d and loses 12d — a net addition of 6d. For an 8 mm stirrup around a 200 × 300 mm cage that is 2 × 500 mm + 48 mm = 1.048 m.
Should stirrup dimensions be inside or outside the cage?
Centre-line — the outer dimension of the member less the cover on both faces. Entering the outer size instead overstates every stirrup on the job, and there are usually hundreds of them.
When do I need a lap, and how long should it be?
Whenever a bar is longer than the 12 m it is rolled in. The lap has to be long enough to transfer the force between the two bars: commonly 40d in compression and 50d in tension for Fe500 in M20, though the drawing governs. Laps must also be staggered rather than all falling at the same section, which is a detailing decision no calculator can make.
Why does my schedule differ from the contractor’s?
Usually one of three things: hook allowance taken as 9d against 10d, bend deductions applied or omitted, or stirrups measured to the outside rather than the centre line. Each row here shows its working precisely so the difference can be located rather than argued about.