| Primary value | 230 × 230 mm (G+1) (G+3 → 230 × 450 · G+5 → 400 × 600) |
| Applies to | Symmetric residential RCC framing · Column tributary area 12–25 m² · M25 concrete with Fe500 reinforcement |
| Exceptions | G+1 (ground + 1) → 230 × 230 mm |
| G+2 → 230 × 300 mm | |
| G+3 → 230 × 450 mm or 300 × 450 mm | |
| G+4 → 300 × 600 mm | |
| G+5 to G+7 → 400 × 600 mm | |
| Corner / heavily loaded column → Increase one size class | |
| IS 456 minimum dimension → 200 mm | |
| Measured as | Cross-section dimensions of the column from foundation top to topmost slab. Same size is typically maintained throughout for residential builds; tall buildings step down with height. |
| Source | IS 456 — Clause 25.1.1, 26.5.3 ✓ Verified |
68 related items across IS codes, knowledge articles, design rules, maps and tools
Column sizing is the most-asked thumb rule on Indian construction sites because it sets the structural cost floor and the architectural footprint. The chart above is the compromise between IS 456 minimums (200 mm), masonry alignment (230 mm = 9-inch brick), and axial load capacity that 99% of residential builds use without needing detailed analysis.
230 × 230 mm columns at G+1 are the absolute minimum and assume light spans (≤ 3.5 m) and uniform layout. The moment you cross 4 m bays or 3 storeys, jump straight to 230 × 450. Skipping the upgrade is the #1 cause of column distress visible in older Indian stock.