RC Column Axial Capacity Calculator (IS 456)
Squash capacity of a tied column: concrete plus longitudinal steel.
A 230×450 M25 column with 4-20Ø carries ~1,460 kN factored — about 4 storeys of typical residential tributary. Real columns also bend; this is the upper anchor of the interaction diagram.
Formula
Note: Pure axial with minimum eccentricity only; combined P-M needs interaction charts (SP-16).
RC Column Axial Capacity Calculator (IS 456) is a free column capacity for structural engineers, fabricators and site engineers — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About RC Column Axial Capacity Calculator (IS 456)
Squash capacity of a tied column: concrete plus longitudinal steel. The calculation implements P_u = 0.4f_ck·A_c + 0.67f_y·A_sc (e_min ≤ 0.05D) (IS 456 cl. 39.3). A 230×450 M25 column with 4-20Ø carries ~1,460 kN factored — about 4 storeys of typical residential tributary. Real columns also bend; this is the upper anchor of the interaction diagram.
How to use RC Column Axial Capacity Calculator (IS 456)
- 1Enter Column width in mm.
- 2Enter Column depth in mm.
- 3Enter Longitudinal steel A_sc in mm² (4-20Ø = 1257 · 6-20Ø = 1885 · 8-20Ø = 2513).
- 4Enter f_ck in MPa.
- 5Read Capacity P_u, Steel percentage, ≈ floors @ 600 kN/floor instantly — no submit button needed.
- 6Need US units? Flip the SI/Imperial toggle and every field converts.
Why use RC Column Axial Capacity Calculator (IS 456)?
- ✓Implements the standard formula — P_u = 0.4f_ck·A_c + 0.67f_y·A_sc (e_min ≤ 0.05D)
- ✓Reference cited on-page: IS 456 cl. 39.3
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the RC Column Axial Capacity Calculator (IS 456) use?+
It computes P_u = 0.4f_ck·A_c + 0.67f_y·A_sc (e_min ≤ 0.05D), per IS 456 cl. 39.3. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
A 230×450 M25 column with 4-20Ø carries ~1,460 kN factored — about 4 storeys of typical residential tributary. Real columns also bend; this is the upper anchor of the interaction diagram. Note: Pure axial with minimum eccentricity only; combined P-M needs interaction charts (SP-16).
Can I use this for real structural design?+
It implements the exact textbook/code formula cited below the result and is ideal for sizing, checking and learning. Final designs should be verified by a qualified engineer against the full code with all load cases.
Is the RC Column Axial Capacity Calculator (IS 456) free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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