RCC Lap Length Calculator
Get the development length (Ld) and lap splice length for any bar diameter, concrete grade and steel grade. Every step of the IS 456 calculation is shown, so you can check it.
Inputs
Results update as you tapMore options
Result
Lap length
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Ld (tension)
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Ld (compression)
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Design bond stress τbd
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Steel stress 0.87fy
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Take it to site: Lap Length Excel Toolkit + Field Guide
Every bar size and grade in one printable sheet, with staggering rules and site checklists.
Lap length table
Values in mm, rounded up to the option above, with the multiple of φ shown alongside. The highlighted cell matches your inputs. Uses the minimum-lap and bundled-bar options set above.
How lap length works, with worked examples
IS 456 clauses, staggering, lapping in columns and beams, and common site mistakes, explained step by step.