RL Circuit Transient Calculator
Calculate ideal series-RL step current, inductor voltage, magnetic energy and a time-response curve with mixed physical units.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Use the exponential current solution for a constant-voltage series RL loop, then derive inductor voltage and magnetic energy.
τ=L/R; I(t)=I₀+(V/R−I₀)(1−exp(−t/τ)); energy=LI²/2
Worked example
12 V across total 6 Ω and 30 mH gives τ=5 ms and final current 2 A. From zero current, at 5 ms current is about 1.264241 A.
Assumptions and input details
Ideal lumped, linear inductance and total series resistance, with a constant source after time zero. Initial current may be signed. Saturation, parasitic capacitance, switching transients, temperature changes, current limits and component ratings are excluded. Results describe the chosen model and do not approve a circuit or measurement procedure.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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