Pipe offset multiplier chart
Multiply your offset by the first number for the travel, and by the second for the run. The numbers are 1 ÷ sin(angle) and 1 ÷ tan(angle), to four decimals.
Multipliers by fitting angle
| Angle | Travel = offset × | Run = offset × | 10″ offset: travel | 10″ offset: run |
|---|---|---|---|---|
| 11.25° | 5.1258 | 5.0273 | 51-1/4″ | 50-1/4″ |
| 22.5° | 2.6131 | 2.4142 | 26-1/8″ | 24-1/8″ |
| 30° | 2.0000 | 1.7321 | 20″ | 17-5/16″ |
| 45° | 1.4142 | 1.0000 | 14-1/8″ | 10″ |
| 60° | 1.1547 | 0.5774 | 11-9/16″ | 5-3/4″ |
| 90° | 1.0000 | 0.0000 | 10″ | 0″ |
The last two columns round to the nearest 1/16 inch, as the calculator does. At 90° the line turns straight over: travel equals the offset and the run is 0.
Using the chart
Say the offset is 7 inches and the fittings are 22.5°. Travel = 7 × 2.6131 ≈ 18.29 inches, which is 18-5/16″. Run = 7 × 2.4142 ≈ 16.90 inches, which is 16-7/8″. For an angle that is not in the chart, or for a result already in feet, inches and sixteenths, use the pipe offset calculator.
Smaller angles make a longer travel for the same offset, because the diagonal is flatter. That is the whole pattern in the table: travel goes down and run goes down as the angle goes up, until at 90° the run is gone.
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.