Formula Help: IF/THEN that provides whole number rounded to a given unit of measure

I am looking for help to come up with a formula that provides a result rounded to a given unit of measure.

My duties are to continually analyze the MIN/MAX of what is now 5000 line items (and growing). I am having to manually come up with the result that I am trying to find an equation for. Sure hope someone can help!

Specifics:
COLUMN AJ - the buy unit of measure in which I have to buy a given product
COLUMN AI - where I am currently entering a manual number, and where I hope to use an equation
COLUMN AH - titled MAX CALC - this is an output column that shows how many I need to have on hand based on another calculation. It can change based on a change in lead time and/or change in the number of safety stock days I want.

A few actuals:

equation help sample.PNG


So the examples should show all scenarios; where AH is zero, less than the buy unit, more than the buy unit, equal to the buy unit. If there are any questions, please let me know. This is the first time I'm posting in this forum, and my second forum post ever!

Thanks

Please upload a workbook, this isn't too difficult so should be a quick fix. Thanks

Appreciate the help, TPDave.