Calculator
Choose a mode and enter known values. The layout uses three columns on large screens, two on smaller screens, and one on mobile.
Plotly Graph
The graph changes with the selected result mode.
Example Data Table
These examples use the inductance mode with voltage, current change, and time.
| Voltage (V) | Start Current (A) | End Current (A) | Time (ms) | Inductance (mH) |
|---|---|---|---|---|
| 12 | 0 | 2 | 5 | 30 |
| 24 | 1 | 3 | 4 | 48 |
| 5 | 0.2 | 1.2 | 2 | 10 |
| 48 | 2 | 6 | 8 | 96 |
Formula Used
1) Inductance from voltage, current change, and time
L = V × Δt ÷ ΔI
2) Inductive reactance
XL = 2πfL
3) Stored energy
E = 0.5 × L × I2
4) RL time constant
τ = L ÷ R
Unit notes
1 H = 1000 mH
1 ms = 0.001 s
How to Use This Calculator
- Select the calculation mode that matches your problem.
- Enter the known electrical values in the visible fields.
- Press Calculate to show the result above the form.
- Review the detailed metrics and the Plotly graph.
- Use the export buttons to save result data as CSV or PDF.
- Compare your output with the example table when needed.
FAQs
1) What does mH mean in this calculator?
mH means milliHenry. It is one thousandth of a Henry. This unit is common in power electronics, filters, relays, and switching circuit work.
2) When should I use the voltage and current change mode?
Use it when you know applied voltage, current rise, and change time. It is useful for pulse circuits, driver design, and transient checks.
3) Why does reactance increase with frequency?
Inductive reactance depends directly on frequency. Higher frequency causes stronger opposition to changing current. That is why coils resist AC more at higher frequencies.
4) What does stored energy tell me?
Stored energy shows how much magnetic energy the inductor holds at a given current. It matters in converters, energy transfer stages, and safety reviews.
5) What is the RL time constant used for?
The RL time constant estimates how quickly current rises or decays. It helps predict transient response, settling behavior, and switch timing in resistor-inductor circuits.
6) Can I use this tool for AC and DC work?
Yes. Reactance mode supports AC analysis. Inductance, energy, and time constant modes support transient and DC-related engineering calculations.
7) Why are resistance and frequency included in several modes?
They add practical context to the result. Engineers often need inductance plus reactance, energy, or time constant in one design check.
8) How accurate is this calculator?
It is accurate for ideal formulas and quick engineering estimates. Real inductors may vary because of core material, saturation, winding resistance, and temperature.