Flat Spiral Coil Inductance Calculator

Flat Spiral Coil Inductance Calculator

Calculate the inductance \(L\) using: $$ L = \frac{\mu_0 \, n^2 \, d_{\text{avg}}}{2} \ln\!\left(\frac{2.46}{\gamma}\right) $$

* Enter the inner diameter (\(d_{\text{in}}\)) and outer diameter (\(d_{\text{out}}\)) in millimeters (mm) and the number of turns \(n\). The diameters are converted to meters automatically.

Step 1: Enter Parameters

e.g., 5 mm

e.g., 20 mm

e.g., 10 turns

Formula: $$ L = \frac{\mu_0 \, n^2 \, d_{\text{avg}}}{2} \ln\!\left(\frac{2.46}{\gamma}\right) $$
where \( d_{\text{avg}} = \frac{d_{\text{in}} + d_{\text{out}}}{2} \) and \( \gamma = \frac{d_{\text{out}} – d_{\text{in}}}{d_{\text{out}} + d_{\text{in}}} \).