What is an avoirdupois ounce?
An avoirdupois ounce is the ordinary ounce of the imperial and US customary systems, as opposed to the troy ounce used for gold and silver.
It is equal to 1/16 of a pound or approximately 28.35 grams. The avoirdupois system is based on a pound of 16 ounces, with larger units such as tons and pounds used for heavier measurements.
What are pounds?
Pounds are an imperial unit of weight normally used in the United States but can be found in use in the United Kingdom and Ireland as well. One pound is equal to 0.4536 kilograms.
We provide several conversion calculators from pounds on this site including the most popular: pounds to kilograms.
Note that pounds are normally referring to avoirdupois pounds. This should not be confused with Troy pounds which is used almost exclusively to measure precious metals.