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Concrete-Filled HSS Composite Column Capacity Calculator

Estimate the cross-sectional compressive capacity of a concrete-filled HSS composite column.

Computed in your browser — nothing you enter is uploaded. Figures are presented for United States against IRC 2024, and every formula is cited under regulatory standards below.

Last verified 2026-08-26 · v1.0.0

Market
Imperial · sales tax

Cross-sectional compressive capacity Pno

2745 kN

Check your inputs

This is the zero-length cross-sectional capacity (Pno) for a compact section only — it does NOT include the AISC-required slenderness reduction (Pn = Pno·0.658^(Pno/Pe) using the column's effective stiffness and unbraced length), which will reduce the usable capacity for any column with meaningful slenderness. Consult a structural engineer for final column design.

Running these inputs gives 2745 kN as the cross-sectional compressive capacity pno. Expect some drift against the real job; the calculation is solid but conditions on site are not. Currently reading for United States under IRC 2024 — pick a different market above and the figures re-cast accordingly.

Add the equipment this sizes

This result is a specification — 2,745 kN — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.

Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — confirmed fixes become pinned regression tests.

[Schema Verified] Computed in alignment with American Concrete Institute (ACI 318-19) formulas and International Residential Code (IRC 2024) spatial boundaries.

Regulatory standards & verification citations

  • AISC 360 Chapter I (§I1.2a, §I2.2b): Pno = Fy×As + C2×f'c×Ac, where C2 = 0.85 for rectangular HSS and 0.95 for round HSS (confinement effect)

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Frequently asked questions

Why does round HSS get a higher confinement coefficient (C2) than rectangular HSS?
A round tube confines its concrete infill more uniformly under compression than a rectangular or square tube does, so AISC 360 assigns round HSS a higher C2 value (0.95) than rectangular/square HSS (0.85) to reflect that added confinement contribution to the concrete's strength.
Is this the final usable capacity of the column?
No — Pno is only the cross-sectional (zero-length) compressive capacity. For any column with meaningful unbraced length, AISC 360 requires a slenderness reduction (Pn = Pno·0.658^(Pno/Pe)) that lowers the usable capacity below Pno. This calculator does not perform that reduction.
What areas should I use for As and Ac?
As is the steel HSS wall's own cross-sectional area (from the manufacturer's or AISC shape tables), and Ac is the area of the concrete infill inside the HSS — the two must be measured separately and not double-counted.