The best measure is how much the paper cup will hold?
Which Is The Best Estimate For The Capacity Of A Paper Cup?
Measure the circumference half way up the cup with a flexible tape. Otherwise, measure the diameter with calipers.
Then calculate the volume of the circle and multiply it by the height to get the volume.
Diameter = Circumference / pi
Area = pi * radius2
or pi * (diameter/2)2
Volume is area * height.
This method takes the average area of the cross section at the middle, so you don't have to estimate the angle.
But there's a much more straightforward way of measuring the volume of an object (regardless of the shape). Fill it with water. Pour the water into a graduated cylinder and measure it directly!
Then calculate the volume of the circle and multiply it by the height to get the volume.
Diameter = Circumference / pi
Area = pi * radius2
or pi * (diameter/2)2
Volume is area * height.
This method takes the average area of the cross section at the middle, so you don't have to estimate the angle.
But there's a much more straightforward way of measuring the volume of an object (regardless of the shape). Fill it with water. Pour the water into a graduated cylinder and measure it directly!