Countries that use pounds and ounces:
United States of America (USA) , South Africa, United Kingdom (UK), Eire (ROI), India, Canada, Australia and most Commonwealth countries. gms g sind klos killograms grms gramms grames kilpounds
A rough guide when you are measuring liquids: 1 ml of water equals 1 gram, 1 litre of water weighs approx 1 kg - other liquids may differ.
Wikipedia links covering units of mass show/hide