There are 21 W21 shapes in the AISC Shapes Database v16.0, from W21x44 at 44 lb/ft to W21x275 at 275 lb/ft. All are nominally 21 in deep, but the actual depth runs from 20.7 in to 24.1 in, because adding weight to a rolled shape makes it deeper as well as thicker.
W21 is one of the workhorse floor-beam depths in commercial steel framing, sitting between W18 and W24. It is common wherever a bay is too long for a W18 but the floor sandwich cannot grow enough to take a W24.
W21 Beam Sizes Chart
Every W21 shape, lightest first. Switch the table between inches and millimeters with the buttons.
| Shape | Weight (lb/ft) | Area (in²) | Depth (in) | Flange width (in) | Web (in) | Flange (in) | Ix (in⁴) | Sx (in³) |
|---|---|---|---|---|---|---|---|---|
| W21x44 | 44 | 13 | 20.7 | 6.5 | 0.35 | 0.45 | 843 | 81.6 |
| W21x48 | 48 | 14.1 | 20.6 | 8.14 | 0.35 | 0.43 | 959 | 93 |
| W21x50 | 50 | 14.7 | 20.8 | 6.53 | 0.38 | 0.535 | 984 | 94.5 |
| W21x55 | 55 | 16.2 | 20.8 | 8.22 | 0.375 | 0.522 | 1,140 | 110 |
| W21x57 | 57 | 16.7 | 21.1 | 6.56 | 0.405 | 0.65 | 1,170 | 111 |
| W21x62 | 62 | 18.3 | 21 | 8.24 | 0.4 | 0.615 | 1,330 | 127 |
| W21x68 | 68 | 20 | 21.1 | 8.27 | 0.43 | 0.685 | 1,480 | 140 |
| W21x73 | 73 | 21.5 | 21.2 | 8.3 | 0.455 | 0.74 | 1,600 | 151 |
| W21x83 | 83 | 24.4 | 21.4 | 8.36 | 0.515 | 0.835 | 1,830 | 171 |
| W21x93 | 93 | 27.3 | 21.6 | 8.42 | 0.58 | 0.93 | 2,070 | 192 |
| W21x101 | 101 | 29.8 | 21.4 | 12.3 | 0.5 | 0.8 | 2,420 | 227 |
| W21x111 | 111 | 32.6 | 21.5 | 12.3 | 0.55 | 0.875 | 2,670 | 249 |
| W21x122 | 122 | 35.9 | 21.7 | 12.4 | 0.6 | 0.96 | 2,960 | 273 |
| W21x132 | 132 | 38.8 | 21.8 | 12.4 | 0.65 | 1.04 | 3,220 | 295 |
| W21x147 | 147 | 43.2 | 22.1 | 12.5 | 0.72 | 1.15 | 3,630 | 329 |
| W21x166 | 166 | 48.8 | 22.5 | 12.4 | 0.75 | 1.36 | 4,280 | 380 |
| W21x182 | 182 | 53.6 | 22.7 | 12.5 | 0.83 | 1.48 | 4,730 | 417 |
| W21x201 | 201 | 59.3 | 23 | 12.6 | 0.91 | 1.63 | 5,310 | 461 |
| W21x223 | 223 | 66.5 | 23.4 | 12.7 | 1 | 1.79 | 6,080 | 520 |
| W21x248 | 248 | 73.8 | 23.7 | 12.8 | 1.1 | 1.99 | 6,830 | 576 |
| W21x275 | 275 | 81.8 | 24.1 | 12.9 | 1.22 | 2.19 | 7,690 | 638 |
What W21 Is Used For
The lighter W21 shapes are efficient floor beams; the heavy end of the range is used for transfer girders and columns, where the extra flange matters more than the weight penalty.
The nominal depth is a family name, not a measurement. Every shape above is called W21 and none of them is exactly 21 in deep. Take the real depth from the chart whenever clearance matters. See how to read steel beam sizes for the full convention.
Related Charts
Every W shape in one place: wide flange beam sizes chart. For the metric designations, see wide flange beam sizes in metric. For the naming confusion around H-beams and I-beams, see H-beam vs I-beam.
Source: AISC Shapes Database v16.0, consistent with the AISC Steel Construction Manual, 16th Edition. Last updated: October 2026.
This page is reference information only and is not engineering advice. Sizing a beam needs a licensed engineer. Full disclaimer.