Solenoid Magnetic Field Calculator

The Solenoid Magnetic Field Calculator computes the magnetic flux density B inside a long solenoid carrying a current I, with N turns over a length L.

How to Use Solenoid Magnetic Field Calculator

Enter N, I and L — turns count, current in amperes and solenoid length.
Enter μr — relative permeability of the core (1 for air).
Read B — shown in tesla and gauss for convenience.
Inspect the turns density n = N/L — useful for cross-checking against textbook values.

Formula & Theory — Solenoid Magnetic Field Calculator

n = N / L
B = μ₀ · μr · n · I
μ₀ = 4π × 10⁻⁷  T·m/A

Use Cases for Solenoid Magnetic Field Calculator

Electromagnet design — choose turns and current for a target field strength.
Physics experiments — predict B in Helmholtz-pair and solenoid setups.
Magnetic actuators — size relays and solenoid valves.
Education — visualize how field scales with turns density and current.

Frequently asked questions about Solenoid Magnetic Field Calculator

Is the field really uniform inside the solenoid?

For an ideal infinite solenoid yes. For practical coils there is a strong axial fall-off near the ends; the formula applies near the centre.

What if the core saturates?

When the core saturates, μr drops sharply and the formula over-predicts. Switch to manufacturer B–H curves for high-current designs.

Why convert to gauss?

Gauss (1 T = 10⁴ G) is still common in magnetics literature and helps compare to permanent magnet data sheets.

Is my data stored?

No. All calculations run locally in your browser; nothing is sent to any server.