Quick Reference
Common values for conduit bending in the field.
90° Bend Take-Up (Deduct)
| Size | EMT | Rigid/IMC |
|---|
| 1/2" | 5" | 5-5/8" |
| 3/4" | 6" | 6-1/4" |
| 1" | 8" | 8-5/8" |
| 1-1/4" | 11" | 12-1/4" |
| 1-1/2" | 13" | 14-1/4" |
| 2" | 16" | 20" |
Values may vary slightly by bender manufacturer. Always verify with your bender.
Offset Multipliers & Shrinkage
| Angle | Multiplier | Shrink/inch | Shrink (frac) |
|---|
| 10° | 5.76 | 0.059" | ~1/16" |
| 22.5° | 2.61 | 0.199" | ~3/16" |
| 30° | 2.00 | 0.268" | ~1/4" |
| 45° | 1.41 | 0.414" | ~3/8" |
| 60° | 1.15 | 0.577" | ~9/16" |
Spread = Rise × Multiplier. Shrinkage per inch of rise.
Saddle Spacing Reference
| Type | Angles | Spacing Formula |
|---|
| 3-Point | 45° / 22.5° / 22.5° | Height × 2.5 |
| 4-Point (22.5°) | 22.5° × 4 | Height × 2.6 |
| 4-Point (30°) | 30° × 4 | Height × 2.0 |
| 4-Point (45°) | 45° × 4 | Height × 1.41 |
Conduit Support Requirements (NEC)
| Type | Max Span | From Term. |
|---|
| EMT (all sizes) | 10 ft | 3 ft |
| IMC (all sizes) | 10 ft | 3 ft |
| Rigid ≤ 3/4" | 10 ft | 3 ft |
| Rigid 1" | 12 ft | 3 ft |
| Rigid 1-1/4" to 1-1/2" | 14 ft | 3 ft |
| Rigid 2" to 2-1/2" | 16 ft | 3 ft |
| Rigid 3" and larger | 20 ft | 3 ft |
Verify with current NEC edition and local amendments.
Conduit Fill Limits (NEC Ch. 9)
| Conductors | Max Fill % |
|---|
| 1 conductor | 53% |
| 2 conductors | 31% |
| 3 or more | 40% |
Trig Values for Common Angles
| Angle | sin | cos | tan |
|---|
| 10° | 0.1736 | 0.9848 | 0.1763 |
| 22.5° | 0.3827 | 0.9239 | 0.4142 |
| 30° | 0.5 | 0.866 | 0.5774 |
| 45° | 0.7071 | 0.7071 | 1 |
| 60° | 0.866 | 0.5 | 1.7321 |
| 90° | 1 | 0 | ∞ |
Concentric Bend Additions
| Spacing (O.C.) | Add per conduit |
|---|
| 1-1/2" | 2-3/8" |
| 2" | 3-1/8" |
| 2-1/2" | 3-15/16" |
| 3" | 4-11/16" |
| 4" | 6-1/4" |
For 90° bends. Add this amount to mark location for each additional parallel conduit. Formula: spacing × π/2 ≈ spacing × 1.5708
All values based on NEC 2023. Always verify with current code and local amendments.