Hi,
During PO creation you have default LB order unit!
Did you have order unit as LB in purchasing view of material master or variable order unit active for your material master in purchasing view?
But what is your UOM for material ?
You can find details in additional data for your material master but in general conversion
1KG=2.201LB
OR
1LB=0.454KG
Regards,
Biju K