A steel beam size such as W16x26 packs three facts into one label: the shape type (W = wide flange), the nominal depth in inches (16) and the weight in pounds per foot (26).
Steel Shape Designations
| Example | Shape type | What the numbers mean | Weight (lb/ft) |
|---|---|---|---|
| W16x26 | Wide flange | 16 in nominal depth, 26 lb/ft | 26 |
| S8x23 | American Standard I-beam | 8 in depth, 23 lb/ft | 23 |
| HP12x53 | Bearing pile (H-pile) | 12 in nominal depth, 53 lb/ft | 53 |
| C8x11.5 | American Standard channel | 8 in depth, 11.5 lb/ft | 11.5 |
| L4x4x1/2 | Angle | 4 in by 4 in legs, 1/2 in thick | 12.8 |
| HSS6x6x1/4 | Square hollow structural section | 6 in by 6 in outside, 1/4 in nominal wall | 19.02 |
Nominal Depth vs Actual Depth
The first number is a nominal size, not an exact measurement. Within a series, heavier shapes are deeper:
| Shape | Weight (lb/ft) | Actual depth (in) | Flange width (in) |
|---|---|---|---|
| W14x22 | 22 | 13.7 | 5 |
| W14x90 | 90 | 14 | 14.5 |
| W14x873 | 873 | 23.6 | 18.8 |
Always use the actual dimensions from a size table, never the nominal number.
W Beam vs I-Beam
W shapes (wide flange) have parallel inner flange faces. S shapes (American Standard beams) have narrower, sloped flanges. In everyday use, both are often called I-beams.
Metric Designations
In metric, the depth is in millimeters and the weight in kilograms per meter. W16x26 is W410x38.8: 399 mm deep, 38.8 kg/m.
Look up any size in the wide flange beam sizes chart or get total weight with the I-beam weight calculator.
Source: AISC Shapes Database v16.0, consistent with the AISC Steel Construction Manual, 16th Edition. Last updated: September 2026. Reference information only, not engineering advice. Disclaimer.