Question 1

How do I calculate inductance from turns?

Accepted Answer

Use the formula L = AL × N², where L is inductance in nanohenries (nH), AL is the inductance factor of your magnetic core (nH/N²), and N is the number of turns. Simply multiply the AL value by the square of the number of turns.

Question 2

How do I calculate the number of turns for a target inductance?

Accepted Answer

Rearrange the formula: N = √(L / AL). Divide your target inductance (in nH) by the AL value of your core, then take the square root of the result to get the required number of turns.

Question 3

What is the AL value of a magnetic core?

Accepted Answer

The AL value (inductance factor) is a specification provided by core manufacturers. It indicates the inductance produced per turn squared, typically expressed in nH/N². Common values range from 16 nH/N² for high-frequency ferrites to over 10,000 nH/N² for high-permeability cores.

Inductance/Turns Calculator

Calculator

Formula Reference

Recommended Inductors

SRP4021HMT-3R3M

SRP2512A-3R3M

SRP3020CC-3R3M