W18X40 Dimensions & Weight
W18X40 is an AISC wide-flange (W) shape with an actual depth of 17.9 in and a 6.02 in wide flange, weighing 40 lb per foot — a workhorse size for floor beams and roof framing on commercial jobs.
W18X40 Dimensions
| Property | Imperial | Metric |
|---|---|---|
| Depth (d) | 17.9 in | 454.7 mm |
| Flange width (bf) | 6.02 in | 152.8 mm |
| Cross-section area (A) | 11.8 in² | 76.1 cm² |
| Weight | 40 lb/ft | 59.5 kg/m |
What does W18X40 cost?
At an example material price of $0.92/lb, W18X40 runs about $36.80 per foot, or roughly $736 for a 20-ft length.
Example pricing only. Actual steel pricing varies by region, grade, quantity, and market conditions — use your own supplier numbers for real bids.
Counting W18X40s off a drawing set by hand? SteelFlo finds every steel label on your PDF automatically — 3 takeoffs free.
Related sizes
Deeper reading: Wide-Flange Beam Sizes: The Complete Guide · How to calculate steel weight