"If VLOOKUP can't find lookup_value, and range_lookup is TRUE, it uses the largest value that is Less than or Equal to lookup_value."

Question:
How to find the minimum value that is greater or equal to lookup_value? For example, in a array 1,2,3,4,5, how can I identify the minimum value, say 3, that is greater than, say 2.5?
Thanks.