Introduction
A square tube is a hollow metal shape with four equal sides and a uniform wall thickness. It is used in frames, supports, fences, and many structural projects. To plan your project and buy the right amount of material, you need to know how much your square tubing will weigh.
This Square Tube Weight Calculator helps you find the weight of any square tube in seconds. Just enter the outer side width, wall thickness, length, and the number of pieces. Then pick your material — such as mild steel, stainless steel, aluminum, copper, brass, or titanium — and the tool does the rest. It uses the standard formula: Weight = (A² − (A − 2t)²) × Length × Density, where A is the outer side width and t is the wall thickness.
The calculator gives you the weight per meter, weight per piece, and the total weight for all pieces. It also shows the cross-sectional area, inner side width, and a handy weight distribution chart. You can switch between millimeters, centimeters, inches, feet, meters, and yards, so it works no matter what units you prefer.
How to Use Our Square Tube Weight Calculator
Enter the size and material of your square tube below. The calculator will give you the weight per meter, weight per piece, and total weight for all pieces.
Outer Side Width (A): Type the outside width of one side of the square tube. Pick your unit from the dropdown (mm, cm, inches, feet, meters, or yards).
Wall Thickness (t): Type how thick the tube wall is. This must be less than half the outer side width. Choose your unit from the dropdown.
Length (L): Type the length of one piece of square tube. Select your unit from the dropdown.
Quantity (Pieces): Type the number of pieces you need. This must be a whole number of at least 1.
Material Type: Pick your material from the list. Options include mild steel, stainless steel, aluminium, copper, brass, and titanium. The density fills in automatically based on your choice.
Click the Calculate button to see your results. Click Reset to clear all fields and start over.
What Is a Square Tube?
A square tube is a hollow metal shape with four equal sides and a square cross-section. It is different from a solid bar because it has empty space inside. The wall thickness tells you how thick the metal is on each side. Square tubes are widely used in construction, fencing, frames, furniture, and machine building because they are strong, lightweight, and easy to weld or bolt together.
How Square Tube Weight Is Calculated
To find the weight of a square tube, you need three measurements: the outer side width, the wall thickness, and the length. First, you calculate the cross-sectional area of the metal by subtracting the inner hollow square from the outer square. The formula is:
Cross-sectional Area = (Outer Width)² − (Outer Width − 2 × Wall Thickness)²
Next, you multiply that area by the length of the tube to get the volume of metal. Then you multiply the volume by the density of the material to get the weight. Different metals have different densities. For example, mild steel has a density of 7.85 g/cm³, while aluminium is much lighter at 2.70 g/cm³. If you need to calculate the weight of other metal shapes, our Metal Weight Calculator and Steel Weight Calculator are also helpful tools.
Why Knowing the Weight Matters
Knowing the weight of square tubes helps you plan projects correctly. You need it to estimate shipping costs, check if a structure can support the load, and order the right amount of material. Builders, engineers, fabricators, and metal suppliers all use weight calculations daily. Getting the weight right saves time, money, and prevents structural problems. For shipping logistics, you may also want to check the Volumetric Weight Calculator to compare actual weight versus dimensional weight for freight purposes.
Common Materials for Square Tubes
Square tubes are made from many types of metal. Mild steel is the most common choice because it is affordable and strong. Stainless steel (like 304 or 316 grades) resists rust and is used where moisture is present. Aluminium square tubes are popular when low weight matters, such as in aerospace or lightweight frames — you can use our Aluminum Weight Calculator specifically for aluminium projects. Copper, brass, and titanium tubes are used for special purposes like plumbing, decoration, or high-performance applications. If you are working with round hollow sections instead, our Pipe Weight Calculator can help you determine weights for cylindrical tubing, while the Plate Weight Calculator is useful for flat metal sheets.