HELP! inventory wekly usage average

[thibby]

I'm putting together a spreadsheet for a client who buys chemicals fro
me.

I visit the site once a week and manually input the current inventorie
and current product feedrates in mililiters per minute which the
converts that to gallons/pounds per day.

I can't for the life of me figure out how to take the inventory fro
week one to week two and formulate a colume which will calculat
weekly/daily average usages based on inventories.

This should be simple but the problem I have is if a delivery is mad
midweek it throws me off.

I also need to convert the daily to weekly to monthly chemical usag
rates per day/week/month but I'm stumped.

Any help please???

Thibb

 

[thibby]

Can anyone help me please