Centerline values for a simple offset made with two fittings of the same angle. Travel, the center-to-center length along the angled pipe, is the offset × 1 ÷ sin of the fitting angle; run, how far along the second fitting sits, is the offset × 1 ÷ tan of the angle. The offset is measured center to center of the two parallel pipes.
These are center-to-center lengths. For a cut length, subtract each fitting's take-out from the travel, and verify with your fitting's dimensions: take-outs vary by maker and pipe type.
Offset multipliers by fitting angle
Travel and run multipliers| Fitting angle | Travel multiplier | Run multiplier |
|---|
| 11¼° | 5.126 | 5.027 |
|---|
| 22½° | 2.613 | 2.414 |
|---|
| 30° | 2.000 | 1.732 |
|---|
| 45° | 1.414 | 1.000 |
|---|
| 60° | 1.155 | 0.577 |
|---|
Travel and run for common offsets
Center-to-center travel and run for offsets from 2" to 36". Example: a 12" offset with 45° fittings has 12 × 1.414 = 16.97" of travel, shown as 17", and 12" of run.
11¼° fittings| Offset | Travel | Run |
|---|
| 2" | 10 1/4" | 10 1/16" |
|---|
| 3" | 15 3/8" | 15 1/16" |
|---|
| 4" | 20 1/2" | 20 1/8" |
|---|
| 5" | 25 5/8" (2' 1 5/8") | 25 1/8" (2' 1 1/8") |
|---|
| 6" | 30 3/4" (2' 6 3/4") | 30 3/16" (2' 6 3/16") |
|---|
| 8" | 41" (3' 5") | 40 3/16" (3' 4 3/16") |
|---|
| 10" | 51 1/4" (4' 3 1/4") | 50 1/4" (4' 2 1/4") |
|---|
| 12" | 61 1/2" (5' 1 1/2") | 60 5/16" (5' 5/16") |
|---|
| 15" | 76 7/8" (6' 4 7/8") | 75 7/16" (6' 3 7/16") |
|---|
| 18" | 92 1/4" (7' 8 1/4") | 90 1/2" (7' 6 1/2") |
|---|
| 24" | 123" (10' 3") | 120 5/8" (10' 5/8") |
|---|
| 30" | 153 3/4" (12' 9 3/4") | 150 13/16" (12' 6 13/16") |
|---|
| 36" | 184 1/2" (15' 4 1/2") | 181" (15' 1") |
|---|
22½° fittings| Offset | Travel | Run |
|---|
| 2" | 5 1/4" | 4 13/16" |
|---|
| 3" | 7 13/16" | 7 1/4" |
|---|
| 4" | 10 7/16" | 9 11/16" |
|---|
| 5" | 13 1/16" | 12 1/16" |
|---|
| 6" | 15 11/16" | 14 1/2" |
|---|
| 8" | 20 7/8" | 19 5/16" |
|---|
| 10" | 26 1/8" (2' 2 1/8") | 24 1/8" (2' 1/8") |
|---|
| 12" | 31 3/8" (2' 7 3/8") | 29" (2' 5") |
|---|
| 15" | 39 3/16" (3' 3 3/16") | 36 3/16" (3' 3/16") |
|---|
| 18" | 47 1/16" (3' 11 1/16") | 43 7/16" (3' 7 7/16") |
|---|
| 24" | 62 11/16" (5' 2 11/16") | 57 15/16" (4' 9 15/16") |
|---|
| 30" | 78 3/8" (6' 6 3/8") | 72 7/16" (6' 7/16") |
|---|
| 36" | 94 1/16" (7' 10 1/16") | 86 15/16" (7' 2 15/16") |
|---|
30° fittings| Offset | Travel | Run |
|---|
| 2" | 4" | 3 7/16" |
|---|
| 3" | 6" | 5 3/16" |
|---|
| 4" | 8" | 6 15/16" |
|---|
| 5" | 10" | 8 11/16" |
|---|
| 6" | 12" | 10 3/8" |
|---|
| 8" | 16" | 13 7/8" |
|---|
| 10" | 20" | 17 5/16" |
|---|
| 12" | 24" (2' 0") | 20 13/16" |
|---|
| 15" | 30" (2' 6") | 26" (2' 2") |
|---|
| 18" | 36" (3' 0") | 31 3/16" (2' 7 3/16") |
|---|
| 24" | 48" (4' 0") | 41 9/16" (3' 5 9/16") |
|---|
| 30" | 60" (5' 0") | 51 15/16" (4' 3 15/16") |
|---|
| 36" | 72" (6' 0") | 62 3/8" (5' 2 3/8") |
|---|
45° fittings| Offset | Travel | Run |
|---|
| 2" | 2 13/16" | 2" |
|---|
| 3" | 4 1/4" | 3" |
|---|
| 4" | 5 11/16" | 4" |
|---|
| 5" | 7 1/16" | 5" |
|---|
| 6" | 8 1/2" | 6" |
|---|
| 8" | 11 5/16" | 8" |
|---|
| 10" | 14 1/8" | 10" |
|---|
| 12" | 17" | 12" |
|---|
| 15" | 21 3/16" | 15" |
|---|
| 18" | 25 7/16" (2' 1 7/16") | 18" |
|---|
| 24" | 33 15/16" (2' 9 15/16") | 24" (2' 0") |
|---|
| 30" | 42 7/16" (3' 6 7/16") | 30" (2' 6") |
|---|
| 36" | 50 15/16" (4' 2 15/16") | 36" (3' 0") |
|---|
60° fittings| Offset | Travel | Run |
|---|
| 2" | 2 5/16" | 1 1/8" |
|---|
| 3" | 3 7/16" | 1 3/4" |
|---|
| 4" | 4 5/8" | 2 5/16" |
|---|
| 5" | 5 3/4" | 2 7/8" |
|---|
| 6" | 6 15/16" | 3 7/16" |
|---|
| 8" | 9 1/4" | 4 5/8" |
|---|
| 10" | 11 9/16" | 5 3/4" |
|---|
| 12" | 13 7/8" | 6 15/16" |
|---|
| 15" | 17 5/16" | 8 11/16" |
|---|
| 18" | 20 13/16" | 10 3/8" |
|---|
| 24" | 27 11/16" (2' 3 11/16") | 13 7/8" |
|---|
| 30" | 34 5/8" (2' 10 5/8") | 17 5/16" |
|---|
| 36" | 41 9/16" (3' 5 9/16") | 20 13/16" |
|---|
Parallel offsets (equal spread)
When several pipes run side by side and make the same offset, each next pipe starts its offset further along the run by spacing × tan(angle ÷ 2), so the spacing stays the same through the travel. Travel and run are the same for every pipe. Example: pipes 12" apart with 45° fittings: 12 × 0.414 = 4.97", shown as 5".
Advance per inch of spacing, tan(angle ÷ 2)| Fitting angle | Advance per inch of spacing |
|---|
| 11¼° | 0.098 |
|---|
| 22½° | 0.199 |
|---|
| 30° | 0.268 |
|---|
| 45° | 0.414 |
|---|
| 60° | 0.577 |
|---|
Advance for common spacings (center to center)| Spacing | 22½° | 45° | 60° |
|---|
| 3" | 5/8" | 1 1/4" | 1 3/4" |
|---|
| 4" | 13/16" | 1 11/16" | 2 5/16" |
|---|
| 6" | 1 3/16" | 2 1/2" | 3 7/16" |
|---|
| 8" | 1 9/16" | 3 5/16" | 4 5/8" |
|---|
| 10" | 2" | 4 1/8" | 5 3/4" |
|---|
| 12" | 2 3/8" | 5" | 6 15/16" |
|---|
| 18" | 3 9/16" | 7 7/16" | 10 3/8" |
|---|
| 24" | 4 3/4" | 9 15/16" | 13 7/8" |
|---|
Lengths are rounded to the nearest 1/16" (feet and inches in brackets from 2 ft) and multipliers to three decimals.
Estimates only. Check measurements, product labels and local building codes before you buy or build.