Inductance Solenoid Calculator

Enter solenoid parameters

Turns (N)

Total winding turns around the core.

Coil length (l)

Use the winding length along the axis.

Geometry input

Choose how you want to define size.

Radius (r)

Used to compute area A = πr².

Core material preset

Presets are approximate and vary by grade.

Relative permeability (μr)

Use 1 for air, higher for magnetic cores.

Frequency (optional)

Computes X_L = 2πfL.

Current (optional)

Computes stored energy and estimated field.

Formula used

For a long solenoid, inductance is approximated by:

L = μ₀ μ_r N² A / l

μ₀ is the permeability of free space (4π×10⁻⁷ H/m).
μ_r is the relative permeability of the core.
N is the number of turns, A is cross-sectional area, l is coil length.

Optional calculations: X_L = 2πfL, U = ½LI², and B ≈ μ₀μ_rNI/l.

How to use this calculator

Enter turns, coil length, and a geometry method.
Pick a core preset or enter μr directly.
Optionally add frequency and current for extra outputs.
Press Calculate to view results above the form.
Use CSV for spreadsheets, or PDF for print-ready output.

For best accuracy, keep units consistent and verify physical dimensions. Real coils may deviate due to fringing fields, winding spacing, and core saturation.

Example data table

Turns (N)	Length (m)	Radius (m)	μr	Inductance (H)
500	0.20	0.010	1	4.9348×10⁻⁴
1000	0.10	0.015	2000	1.7765×10¹
200	0.05	0.005	1	7.8957×10⁻⁵
800	0.30	0.020	500	1.6844×10⁰
1500	0.25	0.008	60	1.3644×10⁻¹

Values use the long-solenoid approximation with A = πr².