How to use the rl time constant calculator
Find the time constant of an inductor circuit. Enter inductance, resistance, supply voltage in the fields above; the time constant τ, final current are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- L — Inductance (mH)
- R — Resistance (Ω)
- V — Supply voltage (V)
Worked example
With inductance = 50 mH, resistance = 25 Ω, supply voltage = 12 V, the calculator gives time constant τ ≈ 2 ms; final current ≈ 0.48 A.
Frequently asked questions
What is the formula for the rl time constant calculation?
Time constant τ (ms) = L / R. Final current (A) = V / R. Here L is inductance (mH), R is resistance (Ω), V is supply voltage (V).
What inputs do I need for the rl time constant calculator?
You need inductance in mH, resistance in Ω, supply voltage in V. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.