Pipe offset calculator
Enter how far the pipe has to step over and the angle of your fittings. You get the travel (the diagonal) and the run (how far the line advances), to the nearest 1/16 inch. It is free and runs in your browser.
Fitting angle
Travel · diagonal pipe length
14-1/8″
14.14″ · 1′ 2-1/8″
Run · advance along the line
10″
10.00″
travel = offset ÷ sin(angle) · run = offset ÷ tan(angle) · rounded to the nearest 1/16″ · the same engine as the app.
What the two answers mean
A simple offset is a right triangle. The offset is the step between the two parallel pipe runs. The run is how far the line advances along its original direction. The travel is the diagonal between them, the length from one fitting to the other measured along the angled piece.
This calculator gives the travel as a theoretical length. It does not subtract anything for the fittings, so what you actually cut is a separate question.
Typing the offset
Type inches as a decimal (14.5) or the way it reads on a tape (14 5/8 or 14-5/8). Pick a fitting angle, or choose Custom for any angle from 1° to 90°.
- The formula. Travel = offset ÷ sin(angle), run = offset ÷ tan(angle), and the rolling offset version.
- 45 degree offset. Why a 45° offset multiplies by 1.4142.
- Multiplier chart. Travel and run multipliers for 11.25° to 90°.
- Worked examples. Eight offsets worked by hand, step by step.
- FAQ. Short answers, and what the calculator leaves out.
Take it to the jobsite in Pipe Offset Calculator!
For iPhone. Works offline.
This calculator is the app’s simple offset, run in your browser. The app adds rolling offsets, conduit bends, drainage grade and cut lengths, in feet-inches-sixteenths, on a keypad built for gloved hands.
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.