Inductance Converter
Convert Henrys, Millihenrys, Microhenrys, and more.
Typical Inductor Values
| Component / Usage | Value | Application |
|---|---|---|
| RF Choke | 1 µH - 10 mH | Radio Frequency Block |
| Power Supply Choke | 1 H - 10 H | Filtering Mains Hum |
| Small Solenoid | 100 µH - 100 mH | Actuators |
| Earth (Planet) | ~0.7 µH | Theoretical Self-Inductance |
What is Inductance?
Inductance is the property of an electric conductor or circuit that causes an electromotive force to be generated by a change in the current flowing.
Unit Explanations
Henry (H)
The SI derived unit of electrical inductance. Named after Joseph Henry.
Millihenry (mH)
One thousandth of a Henry. Commonly used in audio crossovers and power supplies.
Microhenry (µH)
One millionth of a Henry. Standard unit for RF coils and motherboard VRM inductors.
Explore Related Electrical Tools
Storing Energy in a Magnetic Field
Inductors are one of the three fundamental passive components in electronics (alongside resistors and capacitors). They store energy in a magnetic field created by current flowing through a coil of wire. This property, inductance, is measured in Henrys.
From tiny surface-mount inductors in your phone's power supply to massive transformer coils at power substations, understanding inductance is critical for power electronics, RF design, and motor control.
The Henry (H)
The Henry (symbol: H) is the SI unit of inductance. It is defined as:
In practical terms, a 1 Henry inductor will generate 1 Volt of back-EMF when the current through it changes at a rate of 1 Ampere per second.
Common Unit Prefixes
Inductor Types & Applications
Inductors come in many forms, each suited for specific applications:
High inductance. Power supplies, audio filters, chokes.
RF inductors, EMI suppression, switch-mode power supplies.
RF tuning, antenna matching. No core saturation.
Tiny surface-mount. DC-DC converters, mobile devices.
Coupled inductors. Voltage step-up/down, isolation.
Low EMI, high efficiency. Audio, power filtering.
🔄 The LC Resonant Circuit
When an inductor (L) and capacitor (C) are connected, they form a resonant circuit. Energy oscillates between the magnetic field of the inductor and the electric field of the capacitor at the resonant frequency.
f₀ = 1 / (2π√(LC)). This is the foundation of radio tuning—adjusting L or C to select a specific frequency.
Frequently Asked Questions
What is Inductance?
Inductance is the property of an electrical conductor that opposes a change in the current flowing through it. When current changes, an inductor generates a voltage (back-EMF) that resists the change. This is due to Faraday's Law of Electromagnetic Induction.
What is a Henry (H)?
The Henry (H) is the SI unit of inductance, named after American scientist Joseph Henry. 1 Henry is achieved when a current changing at 1 Ampere per second induces an electromotive force (EMF) of 1 Volt across the inductor.
How do I convert Millihenrys (mH) to Microhenrys (µH)?
Since 1 mH = 1,000 µH, simply multiply the mH value by 1,000. For example, 2.5 mH = 2.5 × 1,000 = 2,500 µH. Conversely, divide µH by 1,000 to get mH.
What is the difference between an Inductor and a Capacitor?
Both are passive energy-storage components, but they store energy differently. A capacitor stores energy in an electric field (between plates). An inductor stores energy in a magnetic field (around a coil). They have opposite behaviors in AC circuits: capacitors block DC and pass AC; inductors pass DC and block AC (at high frequencies).
What is Back-EMF?
Back-EMF (Electromotive Force) is the voltage generated by an inductor when the current through it changes. It opposes the change in current (Lenz's Law). This is why you can't instantly change the current in an inductor—it 'pushes back'. This is also why switching off an inductive load (like a motor) creates a voltage spike.
What is an LC Circuit?
An LC circuit (also called a tank circuit or resonant circuit) consists of an inductor (L) and a capacitor (C) connected together. Energy oscillates between the magnetic field of the inductor and the electric field of the capacitor at a specific resonant frequency: f = 1 / (2π√(LC)). This is fundamental to radio tuning.
How does inductance affect AC circuits?
In AC circuits, an inductor exhibits Inductive Reactance (X_L = 2πfL), which acts like frequency-dependent resistance. Higher frequencies see higher reactance, so inductors act as low-pass filters, blocking high-frequency signals while passing low frequencies (like DC).
What factors affect an inductor's inductance?
Four main factors: Number of Turns (N) (more turns = more inductance), Core Material (iron core vs. air core), Cross-sectional Area of the coil (larger = more inductance), and Length of the coil (shorter = more inductance for a given number of turns).
What is Mutual Inductance?
Mutual Inductance occurs when the magnetic field of one inductor induces a voltage in a nearby inductor. This is the principle behind transformers. The coupling between the inductors is described by the coupling coefficient (k), ranging from 0 (no coupling) to 1 (perfect coupling).
What is the L/R Time Constant?
Similar to the RC time constant for capacitors, the L/R time constant (τ = L/R) describes how quickly current rises or falls in an inductive circuit. After one time constant, the current reaches ~63% of its final value. This is important for relay timing and motor startup.