Although blueberries are different sizes, the average weight of a blueberry is just above half a gram. Small to larger cups average around 190 and 250 blueberries respectively, and one cup of blueberries on average weighs about 140 grams.
There are larger varieties of blueberries that fit 90 or less into a cup. The weight is still approximately the same for the cup, yet each blueberry weighs over 1.5 grams on average. Approximately 3/4 of a pound of blueberries fits into a pint. One hundred and forty grams is almost 1/3 of a pound, so a pound of blueberries is approximately three cups. A person needs about four cups of blueberries to make a blueberry pie.