Determine the inductance of your spiral coils quickly and accurately. This free online calculator simplifies complex calculations for flat air-core coils, essential for RF circuits, antennas, and wireless power applications. Understand the impact of the number of turns, outer, and inner diameters on inductance in microhenries (µH).
Formula:
The calculator uses an approximation of Wheeler's formula for flat spiral coils, assuming an air core:
L = (N2 × Davg) / (C1 + C2 × ρ)
- L: Inductance in Microhenries (µH)
- N: Number of Turns
- Dout: Outer Diameter
- Din: Inner Diameter
- Davg = (Dout + Din) / 2: Average Diameter
- ρ = (Dout - Din) / (Dout + Din): Filling factor
- C1 = 30 (Constant for dimensions in inches)
- C2 = 11 (Constant for dimensions in inches)
Note: For accurate results, ensure Dout > Din.