If the issue is that you are using a range_lookup argument of 1 (TRUE) so that you can find weights like 2.5 kgs, then consider using a Helper Column - which could be hidden - that only contains the number associated with your weights:
With 10.00 kgs in A1, put this in B1 and then hide the column:
This will create a "numerical" 10 which can then be found via a VLOOKUP similar to this:
=VLOOKUP(11, B1:C1, 2, 1)
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