Problem with >= in excel

[UL Excel]

I have 3 columns in excel, all are about 100 rows long.

The columns have headers: Date, Life Stage and Age. In a sperate worksheet I have a column of the 4 stages and total column beside it.

What I want to do is create a formula that picks a life stage and take a certain date which will only take into account that stage after (& including) this particular date so it will give the number of these in the other wotksheet.

I have being using the countif and sumif function but to no avail. Apologies if I'm too vague.

Thanks, for any replies in advance

[shg]

Welcome to the forum.

Be less vague; post a workbook and explain in context.