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Structural · W — wide-flange

W21x57 Steel Beam — Dimensions & Properties

W21x57 weighs 57 lb/ft and is about 21.06 in deep. Below: the full AISC section properties, a scaled cross-section, and a pre-filled weight calculator.

Weight
57lb/ft
Depth
21.06in
Width
6.555in
Area
16.7in²
Shape
W21X57 · W — wide-flange

Enter feet + inches, e.g. 20' or 18' 6".

= 20' (240″)
pcs
Cost estimate (optional)
$/lb

Optional. Prices are volatile — use your current mill/supplier rate.

Total weight
1 × W21X57
1,140lb
Per piece
1140lb
Pieces
1
Total
1140lb
Tons
0.57t
d21.06"bf 6.555"tw 0.405
ƒShow the math
  1. 1.Weight per foot (from AISC)per AISC Shapes Database v16.0

    W21X57 is a listed shape; its nominal weight is a published property.

    = 57 lb/ft
  2. 2.Length in feet
    length (in) ÷ 12
    240 ÷ 12
    = 20 ft
  3. 3.Weight per piece
    weight per foot × length
    57 × 20
    = 1140 lb
  4. 4.Total weight
    weight per piece × quantity
    1140 × 1
    = 1140 lb
  5. 5.Convert to tons
    total lb ÷ 2000
    1140 ÷ 2000
    = 0.57 tons

Section properties

Geometry
Weight
57lb/ft
Area, A
16.7in²
Depth, d
21.06in
Flange width, bf
6.555in
Flange thick, tf
0.65in
Web thick, tw
0.405in
Strong axis (x-x)
Ix
1,170in⁴
Sx
111in³
Zx
129in³
rx
8.36in
Weak axis (y-y)
Iy
30.6in⁴
Sy
9.35in³
Zy
14.8in³
ry
1.35in
Torsion & warping
J
1.77in⁴
Cw
3,190in⁶
Before you rely on this
  • Listed weight is the AISC theoretical (nominal) weight per foot. Actual mill weight varies within ASTM rolling tolerance, roughly ±2.5%.
  • This is bare member steel only. Add plates, stiffeners, connections, bolts, and coatings for a full erected-steel takeoff.

Similar shapes

Same series and nearest depths — compare weight and section modulus when you are sizing.

W21x44 44 lb/ftW21x50 50 lb/ftW21x62 62 lb/ftW21x68 68 lb/ftW21x83 83 lb/ftW21x93 93 lb/ftW21x101 101 lb/ftW21x122 122 lb/ftW18x97 97 lb/ftW24x55 55 lb/ft

W21x57 — questions

How much does a W21x57 weigh per foot?
A W21x57 weighs 57 lb/ft. Over a 20-foot length that is 1,140 lb (0.57 tons); a 30-foot length is 1,710 lb.
What are the dimensions of a W21x57?
W21x57 has an actual depth of 21.06 in and a flange width of 6.555 in, a flange thickness of 0.65 in, and a web thickness of 0.405 in. Cross-sectional area is 16.7 in².
What is the moment of inertia and section modulus of a W21x57?
About its strong axis, W21x57 has a moment of inertia Ix of 1,170 in⁴ and a section modulus Sx of 111 in³, with a plastic section modulus Zx of 129 in³. Use these with your engineer's design values — they are geometric properties, not an allowable load.
What does W21x57 mean?
The W means wide-flange. The first number is the nominal depth in inches and the second is the weight in pounds per foot — so W21x57 is a nominally 21-inch-deep wide-flange beam weighing 57 lb/ft (actual depth 21.06 in).

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Sources & references

Estimates for planning purposes only. Verify all results against the code edition adopted in your jurisdiction and with your Authority Having Jurisdiction (AHJ). This tool is not a substitute for a licensed professional engineer. See our methodology, sources, and code editions.

Data: AISC Shapes Database v16.0, © AISC — used per its developer-use provision.