W21x201 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W21x201 is an American wide-flange beam 23 inches (584.2 mm) deep with a 12.6 in (320 mm) flange, weighing 201 pounds per foot (299.1 kg/m) — that is what the "201" in the designation means. All values below are the standard AISC published section properties used in US structural design, with metric equivalents alongside.
Typical uses: floor and roof framing, columns, headers, and general steel construction. For a quick stiffness check, see the deflection example below or open the beam calculator with your own span and load.
Dimensions
| Depth d | 23 in (584.2 mm) |
| Flange width bf | 12.6 in (320 mm) |
| Web thickness tw | 0.91 in (23.1 mm) |
| Flange thickness tf | 1.63 in (41.4 mm) |
Weight & Cross-Section
| Weight per foot | 201 lb/ft (299.1 kg/m) |
| 20 ft bar | 4,020 lb |
| 40 ft bar | 8,040 lb |
| Area A | 59.3 in² (382.6 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 5,310 in⁴ (221,018 cm⁴) |
| Section modulus Sx | 461 in³ (7,554 cm³) |
| Radius of gyration rx | 9.47 in |
| Moment of inertia Iy | 542 in⁴ (22,560 cm⁴) |
| Section modulus Sy | 86.1 in³ (1,411 cm³) |
| Radius of gyration ry | 3.02 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W21x182 | 22.7 × 12.5 | 182 | 4,730 | 417 | −9 % | −11 % |
| W21x201 (this page) | 23 × 12.6 | 201 | 5,310 | 461 | — | — |
Deflection example
A simply supported W21x201 spanning 37 ft with a 10 kip point load at midspan deflects 0.12 in (E = 29,000 ksi, Ix = 5,310 in⁴). The L/360 serviceability limit for this span is 1.23 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W21x201 beam weigh?
W21x201 weighs 201 pounds per foot (299.1 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 4,020 lb and a 40 ft bar 8,040 lb.
What are the dimensions of a W21x201?
W21x201 is 23 in (584.2 mm) deep with a 12.6 in (320 mm) wide flange. The web is 0.91 in thick and the flanges are 1.63 in thick. Note the actual depth differs from the nominal W21 label — always design with the actual value.
What are the dimensions of a W21x201 in mm?
W21x201 is 584.2 mm deep with a 320 mm wide flange; the web is 23.1 mm and the flange 41.4 mm thick. In metric section properties: Ix = 221,018 cm⁴, Sx = 7,554 cm³.
How much does a W21x201 weigh in kg?
299.1 kg per meter. A 6 m bar weighs 1,795 kg and a 12 m bar 3,590 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W21x201?
About the strong axis, Ix = 5,310 in⁴ (221,018 cm⁴) with section modulus Sx = 461 in³. About the weak axis, Iy = 542 in⁴ and Sy = 86.1 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W21x201 or W21x182 — what does one size down change?
W21x182 is about 9% lighter (182 vs 201 lb/ft) but about 11% less stiff (Ix 4,730 vs 5,310 in⁴). Check deflection before downsizing — stiffness falls much faster than weight.
Values are entered from the governing standard’s published tables and cross-checked programmatically against its mass and section formulas before publication. Spotted an error? Write to advertising@metalabout.net — verified corrections ship within days. About