Stirrup Cutting Length Calculator

Why Contractors Lose Money Here

Stirrups are the most repeated bar on a site: a beam can have dozens and a building thousands. A cutting length that is 20 mm too long is only 20 mm per piece, but it is wasted thousands of times, and a stirrup that is too short does not fit the cage and gets re-cut.

Real Site Example

230 × 450 mm beam, 25 mm clear cover, 8 mm stirrups with 135° hooks (10d): A = 230 − 50 = 180 mm, B = 450 − 50 = 400 mm. Cutting length = 2(180 + 400) + 2 × 80 − 3 × 16 − 2 × 24 = 1,160 + 160 − 48 − 48 = 1,224 mm (cut 1,225 mm). A 4 m span at 150 mm spacing needs 4,000 ÷ 150 + 1 = 27 stirrups = 33.1 m = 13.1 kg.

Professional Best Practices

Write the cutting length and count for each stirrup type in the BBS, cut a trial piece first, and keep the bending jig on site so every stirrup comes out the same size.

Engineering Checklist

• Take the clear cover from the drawing (IS 456 Table 16 by exposure)
• Use out-to-out dimensions with bend deductions — not inner dimensions
• Use 135° hooks in beams and columns, especially in seismic zones
• Check closer spacing near supports and beam–column joints (IS 13920)
• Cut and bend one trial stirrup before the batch

Government & Standards References

• IS 2502 — Code of practice for bending and fixing of bars for concrete reinforcement
• IS 456:2000 — Clause 26.4 (cover), Table 16; Clause 26.5.1.5 (shear reinforcement)
• IS 13920:2016 — hoops with 135° hooks in earthquake-resistant beams and columns
• SP 34 — Handbook on Concrete Reinforcement and Detailing

How Experienced Contractors Handle This

Bar benders work from a BBS with one line per stirrup type, showing shape, cutting length, number and weight, checked by the site engineer before cutting.