We should know the initial information before calculation, afterward, calculations will be carried out. This is a simple calculation, first check the pipe’s inner and outer diameter and length, either practically or theoretically. We have to calculate the volume of the pipe and before volume, we should know about the area of the pipe. It may be confusing for you but don’t worry. Here are some simple methods for understanding, let us do it…
I think, it is easier method to present slides instead to write each and everything in phrase form because the technical calculations are difficult to explain without presenting in slides form. However, in this slide, constant values are given such as pi is 3.1415 for area calculation, 1000 kg/m3 for steel density. These all values will be used in calculations.

Suppose, You have Steel pipe, its nominal diameter is 125mm (5″) and length is 1 meter. How to calculate weight of pipe without water? Now you should check practically dimensions of pipe or take values from standard schedule. While, outser diameter and thickness of pipe is taken from ASTM A53, but you can take dimensions from any standard table but according to pipe schedule or thickness of pipe’s wall then weight of pipe will varies. Here we use values and solve the example#1 with the help of equations. It should now that weight formula is volume multiply by density of steel. Finally, we get the 11.22kg/m weight of steel pipe without water of one meter long pipe.

Here, we will calculate the steel pipe weight along with water with the help of example#2. We will consider all same paramters of pipe but area formula of pipe will change because water will flow or stable inside the diameter of pipe only and resultantly water volume will change i.e. 14.46 kg/m means one meter pipe.

Now we have been calculated the weight of steel pipe and weight of water. Both weights to be added and finally get the 25.68kg/m weight of pipe along with water of one meter lengthy pipe.
You can endorse/verify the above calculations through pipe weight calculator and both results will be same. If you are junior/ beginner then should do manual calculations because you will understand the basics then should move forward in advance through pipe weight calculator. It is my suggestion.
Above all detailed information is briefed in this video form for your easy understanding in Urdu language. Don’t miss the video.