Coil Inductance Calculator Coil Inductance Calculator Coil Inductance Calculator Coil Diameter (cm) Coil Length (cm) Number of Turns Calculate Understanding Coil Inductance Inductance is a property of an electrical conductor by which a change in current through it induces an electromotive force in both the conductor itself and in any nearby conductors. Coil inductance is particularly important in the design of transformers, inductors, and other electromagnetic devices. Formula: The formula used in this calculator is an approximation for air-core coils: L = (r² * N²) / (9r + 10l) Where: L = Inductance in µH (microhenries) r = Radius of the coil in cm N = Number of turns l = Length of the coil in cm Example: Let's calculate the inductance of a coil with these parameters: Diameter: 5 cm (radius = 2.5 cm) Length: 10 cm Number of turns: 100 Plugging these values into the formula: L = (2.5² * 100²) / (9 * 2.5 + 10 * 10) = 62.5 / 122.5 ≈ 51.02 µH Factors Affecting Coil Inductance: Number of turns: More turns increase inductance Coil diameter: Larger diameter generally increases inductance Coil length: Longer coils typically decrease inductance Core material: Air core (as assumed in this calculator) vs. ferromagnetic cores Applications: RF circuits and antennas Power supplies and voltage regulators Filters in audio equipment Sensors and measuring instruments Experiment with different coil parameters using the calculator above to see how they affect the inductance! Subscribe to Updates Get the latest creative news from SmartMag about art & design. By signing up, you agree to the our terms and our Privacy Policy agreement.