Inductance
Calculate inductance of an air-filled cylindrical wire coil. Inductance is a property of an electrical conductor by which a change in current induces an electromagnetic field (EMF). This tool uses the empirical formula for air-core cylindrical coils.
Inductance Calculator
Inductance is a property of an electrical conductor by which a change in current flowing through it induces an electromagnetic field (EMF).
Coil Inductance Formula
For an air-filled cylindrical wire coil:
L = μ₀ n² A / (l + 0.45 d)
Where:
- μ₀ = permeability for vacuum = 4π × 10⁻⁷ H/m ≈ 1.2567 × 10⁻⁶ H/m
- A = cylinder cross-section area (m²)
- n = number of wire turns
- l = length of coil (m)
- d = diameter of coil (m)
Note: This formula is valid for l > 0.5 d
EMF Induced in a Coil
EMF = -L dI / dt
Where:
- L = inductance (henrys, H)
- dI = change in current (amperes)
- dt = time (s)