Pipe offset calculator FAQ
Short answers to what people ask about pipe offsets: the math, the angles, and what this calculator does and does not do.
What are travel and run in a pipe offset?
The offset is the step between the two parallel pipe runs. The run is how far the line advances along its original direction, and the travel is the diagonal between the two fittings. The three are the sides of a right triangle. The formula.
How do you calculate the travel of a 45 degree offset?
Multiply the offset by 1.4142, which is 1 divided by the sine of 45 degrees. A 10 inch offset gives a travel of 14.1421 inches, 14-1/8″, and a run of 10″. 45 degree offset.
What is the multiplier for a 22.5 degree offset?
2.6131 for the travel and 2.4142 for the run. Multiplier chart.
What is the multiplier for a 60 degree offset?
1.1547 for the travel and 0.5774 for the run.
What is the multiplier for an 11.25 degree offset?
5.1258 for the travel and 5.0273 for the run.
How do you calculate a rolling offset?
Take the square root of the set squared plus the roll squared to get the true offset, then divide it by the sine of the fitting angle for the travel, or by the tangent for the run. Rolling offset, with an example.
Does the calculator subtract fitting take-out?
No. It gives the travel as the diagonal of the offset triangle and stops there. It does not subtract anything for the fittings.
Can I type fractions of an inch?
Yes. Type 14.5, 14 5/8 or 14-5/8. Results are shown to the nearest 1/16 inch, with the decimal beneath.
Does it work in millimeters?
No. The calculator takes inches.
What happens at 90 degrees?
The travel equals the offset and the run is 0. The calculator treats any angle of 89.99 degrees or more as 90.
Can I use an angle that is not on the buttons?
Yes. Choose Custom and enter any angle from 1 to 90 degrees.
Is it the same math as the app?
Yes. It is the simple offset from the Pipe Offset Calculator iPhone app, ported to the web, and a test compares the two on a grid of inputs. The app also has rolling offsets, conduit bends, drainage grade and cut lengths, and works offline.
How this was checked
The numbers on this page come from the same formulas as the Pipe Offset Calculator iPhone app, and an automated test compares them with the app’s own code on a grid of inputs (last run ). This is trigonometry, not a code or standards reference, and it does not subtract fitting take-outs. If something here is wrong, tell us at a@noshu.net.