A rolling offset is the length that connects two disjointed pipes. A 45 rolling offset is this length of piping that you need when you use 45-degree connectors, the most common connector type. This length forms the hypotenuse of a triangle whose other sides are the true offset, which is the perpendicular diagonal between the pipes, and a third measurement called the setback. Calculate the rolling offset using the Pythagorean theorem and trigonometry.

Measure the pipes' offset, which is the horizontal distance between their center lines. For example, suppose that two pipes have an offset of 14 inches.

Square the offset. With this example, square 14, giving 196 square inches.

Measure the pipes' rise, which is the vertical distance between their center lines. For example, suppose that the rise is 10 inches.

Square the rise. With this example, square 10, giving 100 square inches.

Add the two squared values together. 196 plus 100 gives 296 square inches.

Find the square root of this sum. The square root of 296 is 17.2 inches.

Divide this length by 0.707, which is the cosine of 45. 17.2 divided by 0.707 is 24.33, or 24 1/3 inches. This is the pipes' rolling offset.