Calculator 03 / NEC Chapter 9 · 300.34
Bend radius
Plan buildable conductor and raceway routing with clear bend-radius guidance and the relevant reference points.
Section 1
Conduit bend radius
Minimum bend radius
5 in
Smallest radius allowed for a 3/4" EMT bend — do not bend tighter than this.
NEC Chapter 9 Table 2
Section 2
Conductor bend radius
Minimum bend radius
1.3 in
External diameter (from Table 5 area): 0.130 in
10 × outer diameter — the minimum bending radius for non-shielded conductors, applied at the inner edge of the bend.
Diameter derived from NEC Ch. 9 Table 5 cross-sectional area — verify against the manufacturer's actual cable diameter.
NEC 300.34 · Chapter 9 Table 5
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How this was calculated
- Raceway bends: look up the minimum radius for the selected raceway and trade size in NEC Chapter 9 Table 2 — 3/4" EMT → 5 in.
- Conductor bends: NEC 300.34 requires a minimum radius of 10 × the overall cable diameter for non-shielded conductors → 10 × 0.13 in = 1.3 in.
- Use whichever is larger when routing a bend that contains both the raceway and the conductors.
Engineering disclaimer: These results are a design aid and must be reviewed by a licensed professional engineer and the authority having jurisdiction. Verify cable manufacturer bend-radius requirements (which may be tighter) and field installation conditions. Rule data is transcribed from NEC Chapter 9 Table 2 for reference — always verify against the current licensed copy of the code.