Calculate piping and conduit rolling offset true travel, roll angle, horizontal run, and cut pipe length between 45°, 22.5°, 30°, and 60° elbow fittings.
Specify vertical elevation rise, lateral roll shift, and elbow fitting angle
Center-to-center height difference
Center-to-center horizontal spread
Fitting degree used for both elbows
Center-to-face deduction per elbow
Subtracted for butt-welded joints (1/8")
Level-bubble alignment reference
Cut Pipe Length: 20.75" (3.25" Total Fitting & Gap Deduction)
√(Rise² + Roll²)
Travel minus deductions
Advancement along pipeline
From plumb vertical
Apprentice pipefitters often calculate travel using only Rise, ignoring the lateral Roll. The pipe is cut inches too short, ruining expensive heavy-wall seamless pipe or welded fittings and halting pipeline installation.
Center-to-center travel is the geometric distance between fitting intersection points. Cutting the pipe to the raw travel length pushes the second elbow far past its tie-in target. Our calculator automatically deducts both fitting takeoffs and weld gaps.
Welders must clock the first elbow at the exact angular rotation so the second elbow lands flush with the downline spool. Guessing the angle creates doglegs and weld strain. Our engine computes the exact roll angle in degrees for digital torpedo levels.
Solving compound right triangles manually on job sites with framing squares and scientific calculators invites arithmetic slip-ups. Our instantaneous solver delivers verified true offset, travel, and cut length in one unified view.
Measure vertical center-to-center elevation change (Rise) and lateral horizontal spread (Roll or Set) in inches or mm.
Select 45° elbows (most common 1.414 multiplier), 22.5° elbows for shallow racks, 30°, or 60° fittings.
Enter the manufacturer center-to-face takeoff dimension for each elbow, along with weld root gap spacing if applicable.
Cut the pipe nipple to the exact computed length and clock the first elbow to the calculated roll angle using a protractor level.
A rolling offset solves two interconnected right-angled triangles in three-dimensional space. The first triangle lies on the cross-sectional plane perpendicular to the pipe run:
The second triangle lies on the diagonal plane formed by the true offset and the forward pipeline advancement (Run). Using the elbow angle ($\theta$), Center-to-Center Travel is derived from the hypotenuse:
For a standard 45° elbow, $\csc(45^\circ) = \sqrt{2} \approx 1.414214$. The cut length of the connecting spool piece is then determined by subtracting the take-off for both fittings: $$\text{Cut Length} = \text{Travel} - 2 \times (\text{Fitting Takeoff}) - 2 \times (\text{Root Gap})$$
Calculates true roll and true offset across both horizontal and vertical displacements simultaneously.
Instant travel length calculations for all industry standard forged and welded pipe fittings.
Deducts elbow takeoffs automatically to give pipefitters the exact cut pipe length between welds.
Displays cut lengths in decimal inches, metric millimeters, and exact jobsite 1/16-inch tape fractions.
A rolling offset occurs when a pipe or electrical conduit must change elevation (Rise) and shift laterally (Roll) simultaneously. Unlike a simple 2D offset that only moves in one plane, a rolling offset traverses a 3D compound angle requiring two matching angled elbows turned at a specific roll rotation.
First, calculate True Offset using the Pythagorean theorem: True Offset = sqrt(Rise² + Roll²). Then, calculate Center-to-Center Travel by dividing True Offset by the sine of the fitting angle: Travel = True Offset / sin(Angle). For standard 45-degree elbows: Travel = True Offset x 1.4142.
Cut Pipe Length equals Center-to-Center Travel minus two fitting take-offs (one for each elbow): Cut Length = Travel - (2 x Take-off). For welded butt-weld fittings, also subtract the root gap spacing between each fitting and the pipe ends.
The angle of roll (rotation angle of the fitting from vertical or horizontal) is found using trigonometry: Angle of Roll = arctan(Roll / Rise) or arctan(Rise / Roll) depending on your reference axis. For example, a 12" Rise and 12" Roll produces an exact 45-degree roll angle.
Standard 45-degree fittings are universally stocked across all pipe materials (carbon steel, PVC, copper, ductile iron) and offer optimal hydraulic flow characteristics with minimal friction loss compared to sharp 90-degree directional turns.
