Wire & Cable Formulas
Wire and cable formulas relate conductor gauge to resistance, current capacity, and voltage drop over distance. These calculators help you pick wire that carries current safely without excessive loss. They are vital for power wiring and long cable runs.
Wire & Cable Formula Calculators
- Wire Resistance R = ρ × L / A
- AWG to Cross-Section Area A = 0.012668 × 92^((36−AWG)/19.5)
- Cable Voltage Drop Vdrop = 2 × I × R/m × L
- Maximum Cable Length L = Vdrop / (2 × I × R/m)
- Skin Effect AC Resistance Rac = Rdc × (1 + (d/(2δ))²)
- Coaxial Cable Impedance Z0 = (138/√εr) × log10(D/d)
- Connector Contact Resistance Rc = ρ / (π × a)
- Cable Shielding Effectiveness SE = 20 × log10(1 + 2πfµσt²)
- AWG Wire Ampacity Estimate I_max ≈ 10^((40 − AWG)/15)
- Coaxial Cable Loss α ≈ R / (2 × Z0) dB/m
- Coax Electrical vs Physical Length l_elec = l_phys × VF
Related Formula Categories
Browse the full formulas index for all 32 categories.