A Ferrite Inductor Calculator helps you quickly find the inductance value of a coil wound on a ferrite core. This is important for designing transformers, filters, and energy storage elements in electronics. By inputting the number of turns, core size, and material properties, you get an accurate inductance value without manual math. This tool saves time for engineers, hobbyists, and students working with radio frequency (RF) circuits, power supplies, and signal processing.
formula of Ferrite Inductor Calculator
Core Inductance Formula:
L = (N² × μ × A) / l
Where:
- L = inductance in henrys (H)
- N = number of turns of wire
- μ = permeability of the core (μ = μ₀ × μr)
- μ₀ = 4π × 10⁻⁷ H/m (permeability of free space)
- μr = relative permeability of the ferrite material
- A = cross-sectional area of the core (in m²)
- l = magnetic path length of the core (in meters)
Expanded:
μ = μ₀ × μr
This shows how the core material’s properties boost the inductance compared to an air-core coil.
Common Reference Table
| Term | Meaning | Typical Unit or Note |
|---|---|---|
| L | Inductance | Henries (H) |
| N | Number of Turns | integer |
| μ₀ | Permeability of free space | 4π × 10⁻⁷ H/m |
| μr | Relative permeability | 20–2000 for ferrites |
| A | Cross-sectional area | m² |
| l | Magnetic path length | meters (m) |
This table makes it easy to identify each value needed for accurate calculation.
Example of Ferrite Inductor Calculator
Scenario:
You have a ferrite core with:
- N = 25 turns
- μr = 1000
- A = 0.0002 m²
- l = 0.05 m
Step 1:
Calculate μ = μ₀ × μr
μ = (4π × 10⁻⁷) × 1000
μ ≈ 1.2566 × 10⁻³ H/m
Step 2:
Use the formula:
L = (25² × 1.2566 × 10⁻³ × 0.0002) / 0.05
L = (625 × 2.5132 × 10⁻⁷) / 0.05 ≈ 3.1415 × 10⁻³ H ≈ 3.14 mH
So, the inductor has an approximate inductance of 3.14 millihenries.
Most Common FAQs
A: Ferrite cores increase inductance without needing more turns, saving space and improving efficiency, especially for high-frequency circuits.
A: It provides a good estimate. Real-world inductance may vary due to winding arrangement, core shape, and frequency effects. Always validate with a measurement when precision is critical.
A: Yes, as long as you know the core’s effective area and path length. Common shapes include toroids, E-cores, and rods.