usage formula based on stock movement

[paul51]

Hello to everyone, i have created a.spreadsheet with stock items i would to have a.formula in a column that calculates the usage of that item perhaps then.i could copy the formula down. Is this possible because i have tried without success i await your kind replies
Paul

 

[chetanmehra1989]

can u please explain with the help of example so that i could help u

 

[paul51]

Thank you for replying, i have about 150 items i need to keep track of, i have created a.database for this project , what i am after is i would like to keep an history of what sells better than others, i dont have a transaction list otherwise i could create one from this, sobis there a.formula to input into my.excel database to show what sells better than others,
Thank you in advance