The avoirdupois pound ( 0.45359237 kilogram ) is used in :
United States of America (USA) , South Africa, United Kingdom (UK), Republic of Ireland (ROI) and many former British colonies.
A rough guide when you are measuring liquids: 1 ml of water equals 1 gram, 1 litre of water weighs approx 1 kilo - other liquids may differ.
How to Convert grams into ounces, the actual formula
Multiply the grams by 0.0353 to get ounces
4 g = 0.1412 oz
Answer = int(4 * .0353) [0 oz]
To convert ounces to pounds and ounces (rather than decimal fractions of a pound) use the following formula
oz_start = 0
lb_calc = int(oz_start/16) [therefore lb_calc == 0 lb]
oz_calc = 0 - (lb_calc * 16) [therefore oz_calc = 0 oz]
Answer = lb_calc, oz_calc [0 lb, 0 oz]
Wikipedia links covering units of mass show/hide