The best measure is how much the paper cup will hold?

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 * radius

or pi * (diameter/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 * radius

^{2}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!