US Steel Weight Calculator — Weight Tables and Formulas

Complete guide to calculating steel weight for US structural shapes. Covers weight calculation formulas for W-shapes, HSS (rectangular and round), angles, channels, plates, and bars. Includes weight tables for the most commonly specified sections, material takeoff estimation methods, and the relationship between weight and structural properties per the AISC 16th Edition Steel Construction Manual.

Related pages: AISC Steel Manual | AISC 360-22 Code Notes | US Beam Design | Steel Weight Calculator | US Steel Beam Sizes | HSS Section Properties

Steel Weight Calculation Basics

The weight of a steel member is calculated from its cross-sectional area and length:

Weight = Area _ Length _ Density

For structural steel:

• Density = 490 lb/ft^3 (0.2833 lb/in^3, 7,850 kg/m^3)
• Weight per foot = Area (in^2) _ 0.2833 _ 12 = Area * 3.40 lb/ft

The AISC Steel Construction Manual provides weight per foot (W) for all standard shapes. This is the nominal weight based on the nominal cross-sectional area. Actual mill weight may vary within ASTM A6 tolerance (typically +/- 2.5% for W-shapes).

Quick Formula

For any shape with known area A (in^2): Weight (lb/ft) = A * 3.40

For a W18x35 with A = 10.3 in^2: W = 10.3 * 3.40 = 35.0 lb/ft (matches the nominal designation)

W-Shape Weight Tables

W-shapes (Wide Flange) are the most commonly used structural steel shapes in US construction. The designation W18x35 means a W-shape with a nominal depth of 18 inches and a weight of 35 pounds per linear foot.

Common W-Shapes — Weight and Properties

Tip: The number after "x" in the designation is the nominal weight in pounds per foot. A W18x35 weighs 35 lb/ft, a W14x82 weighs 82 lb/ft, etc.

Weight Estimation for Preliminary Design

For preliminary sizing, use these rules of thumb:

For columns, weight depends on height, load, and K-factor:

HSS Weight Tables

Hollow Structural Sections (HSS) are available in rectangular, square, and round profiles per ASTM A500 Grade C (Fy = 50 ksi) or ASTM A1085 (Fy = 50 ksi, tighter tolerances).

Rectangular HSS — Common Sizes

Round HSS — Common Sizes

HSS Weight Formula

For rectangular HSS with width b, depth d, and wall thickness t: Weight (lb/ft) = [2*(b + d) - 4*t] _ t _ 3.40

For round HSS with outside diameter D and wall thickness t: Weight (lb/ft) = pi _ (D - t) _ t * 3.40

Angle Weight Tables

Single angles (L-shapes) are specified by leg lengths and thickness. Equal-leg angles have the same leg length; unequal-leg angles have different lengths.

Equal-Leg Angles — Common Sizes

Unequal-Leg Angles — Common Sizes

Channel Weight Tables

C-shapes (American Standard Channels) and MC-shapes (Miscellaneous Channels) are used for bracing, lintels, and secondary framing.

American Standard Channels — Common Sizes

Plate and Bar Weight

For flat plates and bars, weight is calculated from the cross-sectional area:

Weight (lb/ft) = Width (in) _ Thickness (in) _ 3.40

Common Plate Weights

For a 3/4" plate 12 inches wide and 10 feet long: Weight = 0.75 _ 12 _ 3.40 _ 10 / 12 = 30.6 _ 10 = 306 lb

Common Bar Weights

Material Takeoff Estimation

For budgeting and procurement, steel weight is estimated at the project level using these methods:

Method 1 — Framing Plan Takeoff

Count all beams, columns, and braces from the structural drawings. Multiply each member length by its weight per foot. Add 3-5% for connection material (plates, bolts, weld metal) and 1-2% for misclosures and waste.

Method 2 — Weight per Square Foot

For preliminary estimates, use weight per square foot of floor area:

For a 5-story office building with 20,000 sf per floor (100,000 sf total) at 15 psf: Estimated steel = 100,000 * 15 = 1,500,000 lb = 750 tons

Method 3 — Percentage of Structural Cost

Steel weight can also be estimated as a percentage of the total structural cost. For typical US commercial construction, steel represents 15-25% of total construction cost, and structural steel framing represents 25-35% of the steel cost.

Calculator

Calculate the weight of any steel section instantly with our free calculator. Enter a W-shape, HSS, angle, channel, plate, or bar to get weight per foot, total weight for a given length, and material cost estimate.

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FAQ

Q: How much does a W10x49 weigh per foot? A: A W10x49 weighs 49 pounds per linear foot. The number after the "x" in a W-shape designation is always the nominal weight in pounds per foot. For a 20-foot long W10x49: total weight = 49 * 20 = 980 lb = 0.49 tons.

Q: What is the weight of steel per cubic inch? A: Steel weighs 0.2833 lb/in^3 (490 lb/ft^3 or 7,850 kg/m^3). This is the density of carbon and low-alloy structural steels. Stainless steel is heavier at approximately 0.289 lb/in^3 (501 lb/ft^3). Aluminum is much lighter at 0.098 lb/in^3 (169 lb/ft^3).

Q: How do I calculate the weight of an HSS? A: For rectangular HSS: Weight = [2*(b + d) - 4*t] _ t _ 3.40 lb/ft, where b = width, d = depth, t = wall thickness (all in inches). For round HSS: Weight = pi _ (D - t) _ t * 3.40 lb/ft, where D = outside diameter. The AISC Manual provides tabulated weights for all standard HSS sizes.

Q: What is the difference between nominal weight and actual weight? A: Nominal weight is calculated from the nominal cross-sectional dimensions listed in the AISC Manual. Actual weight is measured by the mill and may vary by +/- 2.5% (per ASTM A6 tolerance for W-shapes). For material procurement and cost estimation, always use the nominal weight. For lifting and rigging plans, use the actual mill weight (or add 3% to nominal for a conservative estimate).

Q: How much does structural steel cost per pound? A: In 2024-2026, fabricated structural steel in the US typically costs $1.50-$3.50 per pound installed (including material, fabrication, delivery, and erection). Raw steel (mill price) is approximately $0.40-$0.80 per pound. The wide range depends on project size, complexity, location, market conditions, and the mix of shapes required. Heavy sections (W14 and larger) cost less per pound than lighter sections due to fabrication efficiency.

Related: US Beam Design Guide | US Column Design Guide | AISC Steel Manual | HSS Section Properties | Steel Weight Calculator | Beam Capacity Calculator