Hi Matt.

The total surface area will be the sum of the inside surface area, the outside surface area and the top and bottom rings of the cylinder.

You will need to find the internal radius and external radius from your measurements. Then you can calculate the circumference of the outside and inside. Multiply these by the length of the cylinder to find the inside and outside surface areas.

The top and bottom (which are identical circuar rings, so we can just calculate one and then double it). Find the area of the larger (outside circle) and subtract the smaller (inside circle) to find the ring that is left over.

Cheers,
Stephen La Rocque.