How to calculate expected out of stock

Hi guys,

I was wondering if any of you could help me work out how to do something. Basically I have a stock level and an average run rate. So for example 40 boxes in stock and a run rate of 5. What kind of formula could I use to work out the expected out of stock date, but one that would work for all different levels of stocks and run rate?

Thanks hope you can help,

Sam

attach you working sheet

Have attached an example

How would I do it so the average run rate is per month instead of day? So an average of 5 products a month with 40 stock would show it going out of stock in 8 months

How do I do it so I get the correct year? for example 709 stock and 23 run rate gives me 31/01/1900 when I use =Round(B4/D4,0)