Tube Weight Calculator
Need to calculate the weight of metal tubing? Our handy tube weight calculator will help you calculate the weight of round, square, rectangular, or hexagonal tubes in seconds.
We’ve included a helpful user guide below the calculator if you get stuck. We’ve also written a series of guides to show you to complete the calculation manually if you’d prefer to bypass the calculator.
How to Use the Tube Weight Calculator

The first step is choosing the tube type for your calculation, with round, square, rectangular, and hexagonal tubes available from the ‘Select a Tube Type’ dropdown.

You can change the material used for the tubing in your calculation via the ‘Material’ dropdown in box (2).
The ‘Density’ box will automatically be populated based on the material type you choose.
You can update the ‘Density’ figure if needed, although we’ve based the figure used for each material on industry guidance.
 You can change how many tubes you include in your calculation by updating the ‘Quantity’ dropdown in box (2).

Depending on the tube type chosen for your calculation, you’ll need to enter various dimensions, for example, ‘Length’, ‘Diameter’, ‘Width’, and ‘Thickness’.
The calculator will automatically reformat depending on the type of tube profile chosen, meaning only the relevant dimensions will be shown.
You can select the relevant units for each measurement using the ‘Unit’ dropdowns, including millimeters, centimeters, meters, inches, and feet.
!Note: If you choose ‘inch’ as a unit, you’ll need to use either whole or decimal numbers instead of fractions. For example, 0.25 instead of ^{1}/_{4}.
We’ve included a handy conversion table of standard material dimensions that you can use in the tube weight calculator. Click the button below to view the table:

Tube Weight Calculator – Inch to Decimal Conversion Table 1/8
0.125
19/16
1.5625
35/8
3.625
5/32
0.15625
15/8
1.625
311/16
3.6875
3/16
0.1875
111/16
1.6875
33/4
3.75
7/32
0.21875
13/4
1.75
313/16
3.8125
1/4
0.25
113/16
1.8125
37/8
3.875
9/32
0.28125
17/8
1.875
315/16
3.9375
5/16
0.1325
115/16
1.9375
4
4.00
11/32
0.34375
2
2.00
41/8
4.125
3/8
0.375
21/16
2.0625
43/16
4.1875
13/32
0.40625
21/8
2.125
41/4
4.25
7/16
0.4375
23/16
2.1875
45/16
4.3125
15/16
0.9375
21/4
2.25
43/8
4.375
1/2
0.5
25/16
2.3125
47/16
4.4375
17/32
0.53125
23/8
2.375
41/2
4.50
9/16
0.5625
27/16
2.4375
49/16
4.5625
19/32
0.59375
21/2
2.50
45/8
4.625
5/8
0.625
29/16
2.5625
411/16
4.6875
11/16
0.6875
25/8
2.625
5
5.00
3/4
0.75
211/16
2.6875
51/16
5.0625
13/16
0.8125
23/4
2.75
51/8
5.125
7/8
0.875
27/8
2.875
53/16
5.1875
13/16
0.8125
215/16
2.9375
51/4
5.25
15/16
0.9375
3
3.00
53/8
5.375
1
1.00
31/16
3.0625
57/16
5.4375
11/16
1.0625
31/8
3.125
51/2
5.50
11/8
1.125
33/16
3.1875
55/8
5.625
13/16
1.1875
31/4
3.25
53/4
5.75
11/4
1.25
35/16
3.3125
57/8
5.875
15/16
1.3125
33/8
3.375
515/16
5.9375
13/8
1.375
37/16
3.4375
6
6.00
17/16
1.4375
31/2
3.50
11/2
1.50
39/16
3.5625

 Use the ‘Calculate’ button to complete your calculation, or the ‘Reset’ button to reset the tube bar weight calculator if you want to start over.
How to Calculate Tube Weight
Don’t feel like using our handy tube weight calculator? No problem. We’ll show you how to calculate the weight of metal tubing in this section manually:
 Calculating round tube weight
 Calculating square tube weight
 Calculating rectangular tube weight
 Calculating hexagonal tube weight
How to Calculate the Weight of Round Tube
Calculating the weight of a round tube or pipe is relatively simple, and you can complete the calculation in three distinct steps.
Step One
For the first step, we’ll treat the round tube as if it’s a solid round bar by disregarding the hollow part of the pipe for now.
We can calculate the overall volume as follows:
The equation above consists of the following elements:
V = Volume
π = Pi, or 3.142
r = The radius of the round tube, squared
l = The length of the round tube
To show you how the calculation works, we’ll work through an example of a mild steel round tube with a diameter of 40mm and a length of 1meter.
For this calculation, we’ll be multiplying the Pi figure of 3.142 by the round tube’s radius squared (the radius is half the diameter, so 20mm for this example), and finally, we’ll be multiplying this by the round tube’s length (1meter in this case).
As we’re using a density of 7850 kg/m^{3} for this calculation (i.e., mild steel’s density on a per meter basis), we’ll need to convert each of the other dimensions used in the formula to meters.
We don’t need to change the length as it’s already in meters (1meter in this case), but the 20mm radius should be 0.020 (the radius dimension converted to meters).
We can then calculate the volume of the round tube as if it was a solid bar as follows:
Overall Round Tube Volume = (3.142 x (0.020 x 0.020)) x 1
Overall Round Tube Volume = 0.00126m^{3}
Step Two
Next, we need to calculate the volume of the hollow section of the round tube, and we’ll use the same equation from step one above to do so.
For this example, we’ll assume that the 40mm round tube has a thickness of 8mm, meaning the hollow section of the round tube has a diameter of 24mm (40mm minus the sides which measure 8mm each in thickness).
As above, we’ll need to convert the dimensions to meters to suit the 7850 kg/m^{3} density we’re using for mild steel in the calculation. So, we’ll use a figure of 0.012 for the radius of the hollow section (the radius is half of the diameter, remember).
Here’s how the second part of the calculation works:
Hollow Section Volume = (3.142 x (0.012 x 0.012)) x 1
Hollow Section Volume = 0.00045m^{3}
Step Three
Finally, we need to subtract the volume of the hollow section of the round tube from the tube’s overall volume.
For example:
Total Volume = Overall Round Tube Volume – Hollow Section Volume
Total Volume = 0.00081m^{3}
If we multiply the 0.00081m^{3} volume figure by the 7850 kg/m^{3} density figure for mild steel, we end up with a weight of 6.36 kg or 14.02 lbs for the round tube.
How to Calculate the Weight of Square Tube
As with the round tube weight calculation above, calculating the weight of square tube is a threestep process.
Step One
The first step is to disregard the hollow portion of the square tube altogether and to calculate the overall volume of the tube as if it was a solid square bar.
We can calculate the overall volume as follows:
The equation above consists of the following elements:
V = Volume
w = The width of the square tube, squared
l = The length of the square tube
To show you how the calculation works, we’ll work through an example of a stainless steel square tube with a width of 50mm and a length of 1meter.
For this calculation, we’ll be squaring the width of the square tube to find the crosssectional area (50mm x 50mm in this case, or 2500mm^{2}, and multiplying this figure by the square tube’s length (1meter in this case).
As we’re using a density of 7930 kg/m^{3} for this calculation (i.e., type 304 stainless steel’s density on a per meter basis), we’ll need to convert each of the other dimensions used in the formula to meters.
We don’t need to change the length as it’s already in meters (1meter in this case), but the 50mm width should be 0.050 (the width dimension converted to meters).
We can then calculate the volume of the square tube as if it was a solid square bar as follows:
Overall Square Tube Volume = (0.050 x 0.050) x 1
Overall Square Tube Volume = 0.0025m^{3}
Step Two
Next, we need to calculate the volume of the hollow section of the square tube, and we’ll use the same equation from step one above to do so.
For this example, we’ll assume that the 50mm square tube has a thickness of 10mm, meaning the hollow section of the square tube has a width of 30mm (50mm minus the sides which measure 10mm each in thickness).
As above, we’ll need to convert the dimensions to meters to suit the 7930 kg/m^{3} density we’re using for stainless steel in the calculation. So, we’ll use a figure of 0.030 for the width of the hollow section.
We complete the second part of the calculation as follows:
Hollow Section Volume = (0.030 x 0.030) x 1
Hollow Section Volume = 0.0009m^{3}
Step Three
The final step is to subtract the volume of the hollow section of the square tube from the tube’s overall volume.
In the case of our example:
Total Volume = Overall Square Tube Volume – Hollow Section Volume
Total Volume = 0.0016m^{3}
If we multiply the 0.0016m^{3} volume figure by the 7930 kg/m^{3} density figure for type 304 stainless steel, we end up with a weight of 12.69 kg or 27.97 lbs for the square tube.
How to Calculate the Weight of Rectangular Tube
Calculating the weight of rectangular tubing is similar to that of a square tube. However, while a square has a width and height of the same size, you’ll need to take account of the increase in one of these dimensions when working with a rectangle.
As with the square tube’s calculation, you’ll first need to disregard the rectangular tube’s hollow portion and calculate the overall volume as if the tubing is solid.
The calculation for this is as follows:
The equation above consists of the following elements:
V = Volume
w = The width of the rectangular tube
h = The height of the rectangular tube
l = The length of the square tube
Next, you’ll need to calculate the volume of the hollow portion of the rectangular tube, and you can do this by repeating the formula above with the relevant dimensions for the hollow section.
Finally, you’ll need to subtract the volume of the hollow section from the overall volume of the rectangular tube before multiplying this figure by the density of whichever material you’re using.
How to Calculate the Weight of Hexagonal Tube
As with the other tube profiles in this section, we can calculate the weight of hexagonal tubing in three distinct steps.
Step One
The first step is to determine the overall volume of the hexagonal tube as if it were not hollow, with the equation as follows:
When calculating the weight of hex bar tube, the equation consists of the following elements:
V = Volume
AFW = The ‘across flats’ width of the hex bar
L = The length of the hex bar
Let’s work through an example of a type 304 stainless steel hex tube that has an ‘across flats’ width of 40mm and a length of 2meters.
In this case, we’ll be dividing the square root of 3 (approximately 1.73) by two before multiplying this figure by the acrossflats width (40mm) squared, before finally multiplying this figure by the length of the steel hex tube (2 meters).
Because we’re using a density of 7930 kg/m^{3} for the calculation, we’ll need to convert the dimensions in this example to meters. The length of the bar is already 2meters, so we don’t need to change this, but the 40mm width should be 0.04 (the width dimension converted to meters).
Here’s how the calculation works:
Overall Hex Tube Volume = (((1.73÷2)×(0.04×0.04)×2))
Overall Hex Tube Volume = 0.002768m^{3}
Step Two
The next step is to calculate the volume of the hollow section of the hexagonal tube, and we can use the same equation that we used in step one.
For this example, we’ll assume that the 40mm hexagonal tube has a thickness of 8mm, meaning the hollow section of the square tube has a width of 24mm (40mm minus the two sides which measure 8mm each in thickness).
As above, we’ll need to convert the dimensions to meters to suit the 7930 kg/m^{3} density we’re using for stainless steel in the calculation. So, we’ll use a figure of 0.024 for the width of the hollow section.
Here’s a workthrough of the second part of the calculation:
Hollow Section Volume = (((1.73÷2)×(0.024×0.024)×2))
Hollow Section Volume = 0.00099648m^{3}
Step Three
Finally, we need to subtract the volume of the hollow section of the hex tube (the answer from step two) from the tube’s overall volume (the answer from step one).
Here’s what we end up with:
Total Volume = Overall Hex Tube Volume – Hollow Section Volume
Total Volume = 0.00177152m^{3}
If we multiply the 0.00177152m^{3} volume figure by the 7930 kg/m^{3} density figure for type 304 stainless steel, we end up with a weight of 14.05 kg or 30.97 lbs for the hexagonal tube.
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