You can get size of a complete table from DBC.Tablesize view.By using this view you can estimate the size of partial data.. lets say you have 100 records in your table which is of 10MB size(Tablesize), out of it lets say you have 50 inactive records so you can say,size of Inactive data records is 5 MB. For accurate estimate I think you have to doTable sizing where you consider datatypes, their length etc..
You can get size of a complete table from DBC.Tablesize view.By using this view you can estimate the size of partial data.. lets say you have 100 records in your table which is of 10MB size(Tablesize), out of it lets say you have 50 inactive records so you can say,size of Inactive data records is 5 MB. For accurate estimate I think you have to doTable sizing where you consider datatypes, their length etc..