Stirrup Cutting Length Calculator
Find the cutting length of a stirrup or tie for a beam or column. Pick the shape, enter the member size, clear cover, bar diameter and hook bend, and get the length by the IS 2502 method and by the bend-deduction rule used on site, plus the weight for the number of stirrups you need.
Stirrup Cutting Length Calculator
Planning aid, not a structural design. Stirrup size, spacing, hook and bend details must be confirmed by a qualified structural engineer against the governing code before cutting.
Overall member size, in mm.
- Cutting length (as per experience)
- 1,264 mm
- Cutting length (IS 2502)
- 1,360 mm
- Weight per stirrup (IS 2502)
- 0.537 kg
- Total weight (IS 2502)
- 0.54 kg
- Total length (IS 2502)
- 1.36 m
1 stirrup of 8.0 mm bar at 1,360 mm each: 1.36 m, 0.54 kg.
How this was calculated
- a = A − 2 × cover − d, b = B − 2 × cover − d; hook = 10d / 12d / 14d for 90° / 135° / 180° (site convention; IS 2502 Table II uses 9d–17d by bend radius)
- Rectangular: IS 2502 = 2(a+b) + 2 hook; experience = IS 2502 − 3(2d) − 2(3d)
- Circular: r = D/2 − cover − d/2; IS 2502 = 2πr + 2 hook
- Diagonal: H = √((a/2)² + (b/2)²); IS 2502 = 4H + 2 hook; experience = IS 2502 − 3(2d) − 2(3d)
- Triangular: H = √((a/2)² + b²); IS 2502 = 2H + a + 2 hook; experience = IS 2502 − 4(3d)
- Weight = cutting length (m) × d² / 162.2 kg/m
- Inside side a = 400.0 − 2 × 25.0 − 8.0 = 342.0 mm
- Inside side b = 300.0 − 2 × 25.0 − 8.0 = 242.0 mm
- Hook length = 12 × 8.0 = 96.0 mm
- Cutting length (IS 2502) = 2(342.0 + 242.0) + 2 × 96.0 = 1,360.0 mm
- Cutting length (as per experience) = 1,360.0 − 3(2 × 8.0) − 2(3 × 8.0) = 1,264.0 mm
- Weight per stirrup = 1.360 m × 0.3946 kg/m = 0.537 kg
- Total weight = 0.537 kg × 1 = 0.54 kg
How to use the stirrup calculator
Choose the stirrup shape. For rectangular, diagonal and triangular stirrups enter the overall width A and depth B of the beam or column; for a circular stirrup enter the column diameter D. Then enter the clear cover, the stirrup bar diameter, the hook bend (90°, 135° or 180°, taken as 10, 12 or 14 times the bar diameter) and how many stirrups you need. Bare numbers are read in millimetres (inches in imperial).
The calculator subtracts the cover and the bar diameter to get the inside sides a and b (or the radius r), works out the diagonal leg H by Pythagoras where the shape needs it, and gives two cutting lengths: the IS 2502 length with no bend deductions, and the length "as per experience" that deducts the usual allowance for each bend. Weight uses the IS 2502 length and d² / 162.2 kg per metre.
What you need
The member size from the structural drawing (overall, not the core), the clear cover to the stirrup from the drawing or the general notes, the stirrup bar size (often 8 mm in houses), the hook angle shown in the bar bending details (135° is common for ties in columns and beams), and the stirrup count from the spacing and member length.
Accuracy and limitations
The formulas follow the InsightHub estimating toolkit sheets. Where a sheet cell disagreed with its own stated formula, this calculator uses the stated formula: the rectangular IS 2502 length uses the inside sides a and b, the diagonal and triangular bend deductions are the ones written in the sheet headings, and the circular length uses π rather than 3.14. Bend deductions vary with bar size, bending equipment and site practice, so treat the "as per experience" figure as a guide and check one cut bar against the drawing before cutting a batch. This is a quantity estimate, not a structural design.
Next steps
Use the cutting length in your bar bending schedule. For the full steel take-off of a column, including main bars, use the Steel Quantity Calculator. For slab reinforcement, use the Slab Steel Calculator. Add wastage to the total weight when you order steel.
Frequently asked questions
What is the formula for stirrup cutting length?
For a rectangular stirrup, the IS 2502 cutting length is 2(a + b) + 2 × hook length, where a and b are the inside sides (overall size minus twice the cover minus the bar diameter). The site rule deducts three 90° bends at 2d and two 135° bends at 3d from that.
What hook length should I use?
This calculator takes the hook as 10d for a 90° bend, 12d for 135° and 14d for 180°, where d is the stirrup bar diameter. These are a common site convention, not IS 2502 values: IS 2502 Table II sets the hook allowance by bend radius instead (9d, 11d, 13d or 17d). Use what your drawing specifies if it differs.
Why are there two cutting lengths?
The IS 2502 length adds no bend deductions. Bar benders usually cut a little shorter because a bent bar stretches at each bend; the "as per experience" length subtracts that allowance. Circular stirrups have no bend deduction in the toolkit, so only the IS 2502 length is given.
How is the weight of stirrups calculated?
Weight = cutting length in metres × d² / 162.2 kg per metre × number of stirrups. An 8 mm bar weighs about 0.395 kg per metre.
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