Electronics
Inductance Calculator
Size coil inductance by entering the number of turns, core material, coil area, and length. Great for filters and RF experiments.
Estimate inductance from turns, coil radius, length, and core material.
Solenoid inductance
L = μ₀ μᵣ N² A / l
μ₀ is vacuum permeability (4π × 10⁻⁷ H/m). μᵣ is the relative permeability of the core. A is cross-sectional area (m²) and l is coil length (m).
How to use
- Enter the number of turns and coil dimensions.
- Pick a core material to set the relative permeability or type a custom value.
- Review inductance in henries with millihenry and microhenry conversions.
Example
Input: Turns = 120, Radius = 1.5 cm, Length = 6 cm, Core = Ferrite (μᵣ ≈ 200)
Output: Inductance ≈ 1.35 mH
Student-friendly breakdown
This walkthrough emphasizes the most searched ideas for Inductance Calculator: inductance calculator, coil inductance calculator, solenoid inductance calculator, air core inductance calculator. Start with the formula above, then follow the guided steps to double-check your work. For quick revision, highlight the givens, plug into the equation, and finish by verifying your units.
Need more support? Use the links below to open the long-form guide, browse additional examples, or hop into adjacent calculators within the same topic — each one is a quick way to double-check your work or handle a related question without starting from scratch.
Deep dive & study plan
Inductance Calculator: Estimates inductance for air-core and ferrite-core coils. It's built around inductance, coil, henry, so you can go from a raw question to a checked answer without switching tools.
The math behind it: μ₀ is vacuum permeability (4π × 10⁻⁷ H/m). μᵣ is the relative permeability of the core. A is cross-sectional area (m²) and l is coil length (m). The core relationship is L = μ₀ μᵣ N² A / l, shown above the calculator so you can see exactly how your inputs turn into the result.
To use it well: (1) Enter the number of turns and coil dimensions. (2) Pick a core material to set the relative permeability or type a custom value. (3) Review inductance in henries with millihenry and microhenry conversions. Keep your units consistent as you go, and re-run a case you already know the answer to — it's the fastest way to catch a typo before it throws off a result you're relying on.
Worked example: entering Turns = 120, Radius = 1.5 cm, Length = 6 cm, Core = Ferrite (μᵣ ≈ 200) returns Inductance ≈ 1.35 mH. Try swapping in your own numbers next, especially a case you're unsure about, before you use this for something that matters.
Quick retention checklist
- Speak the formula aloud (or annotate it) so the relationships stick.
- Write each step in your own words and compare with the numbered list above.
- Swap in new numbers for the Example to make sure the calculator (and your logic) handles edge cases.
- Check at least one related calculator below — it's the fastest way to confirm your numbers still line up from a different angle.
FAQ & notes
Does wire thickness matter?
Wire diameter only impacts resistance. Inductance depends on turns, area, length, and core permeability.
Can I use this for toroidal cores?
The formula targets solenoid coils. Modify inputs or use toroid-specific equations for best accuracy.
What formula does the Inductance Calculator use?
μ₀ is vacuum permeability (4π × 10⁻⁷ H/m). μᵣ is the relative permeability of the core. A is cross-sectional area (m²) and l is coil length (m).
How do I use the Inductance Calculator?
Enter the number of turns and coil dimensions. Pick a core material to set the relative permeability or type a custom value. Review inductance in henries with millihenry and microhenry conversions.