This is a nice video which can educate you by creating your own excel formula to find steel bars weight? once you create this formula you will have to enter only the diameter and length of the bar. by entering these two type of information excel will directly give you the weight of that bar.
Here is the process
1- Open your excel and write dia in one cell, length of the bar in another cell and weight
2- Write the following formula in the cell right below that cell in which you have already written weight and then press enter. formula: =(C2^2)*(D2)/162.198
3- Now write the value of diameter and length in their below cells and press enter.
4- look to the weight cell. the weight of the bar is already shown. i think for better understanding lets watch the video.