Solenoid Inductance and Field Calculator
Estimate long-solenoid inductance, interior magnetic field and stored energy from turns, geometry and current.
YOUR CALCULATION
Result
—
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 ideal long-solenoid uniform-field relation with a vacuum-permeability approximation.
L=μ₀N²πr²/length; B=μ₀NI/length; energy=LI²/2
Worked example
Radius 5 mm, length 100 mm and 100 turns give ideal inductance about 9.8696 μH. At 1 A the uniform-field model gives about 1.25664 mT.
Assumptions and input details
Air/vacuum core with uniformly distributed turns. This tool restricts axial length to at least ten radii as a conservative model scope, without an accuracy promise. μ₀ is stored as an explicit numerical approximation. End effects, winding thickness, resistance, self-resonance, heating and added magnetic material are excluded. No wire, current or physical component rating is recommended.
References: OpenStax: cylindrical solenoid self-inductance
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Choose from 23 length definitions, including explicitly labelled regional measures. Area conversions square the length factor; geometric volumes cube it.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
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.
NIST measurement tables · Japanese traditional units · Mainland China and Hong Kong unit distinctions
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.
Calculate ideal series-RL step current, inductor voltage, magnetic energy and a time-response curve with mixed physical units.
Convert magnetic field strength H between A/m, A/cm, kA/m and oersted.
Calculate ideal electrodeposited mass, uniform thickness or elapsed time from entered charge efficiency and material properties.
Reserved advertising space.