Magnetic Field Calculator

Calculate the magnetic field strength (B) for a straight wire, solenoid, or circular loop using Biot-Savart and Ampere's law.

Current

Distance / Length / Radius

Geometry

Number of Turns

Tab to move between fields

Magnetic Field Strength

UnitμT

Formula UsedB = μ₀I / (2πr)

How to Use This Calculator

Enter Current, Distance / Length / Radius, and Geometry.
Set Number of Turns.
Review the Magnetic Field Strength result.
Use Unit and Formula Used to inform your decision.
Use the chart to visualize the results and explore different scenarios by adjusting inputs.

How the result changes with Distance / Length / Radius

Current: Electric current flowing through the conductor in amperes.
Distance / Length / Radius: For wire: distance from wire. For solenoid: length. For loop: radius.
Geometry: 1 = Infinite straight wire, 2 = Solenoid (uses turns & length), 3 = Circular loop (uses turns & radius).
Number of Turns: Number of turns (only used for solenoid and loop geometries).

Identify Input Parameters
4 parameters
Current = 5, Distance / Length / Radius = 0.1, Geometry = 1, Number of Turns = 100 = 4 input(s) provided
Calculate Magnetic Field Strength
10 = 10
Calculate Unit
Unit = displayUnit
μT = μT
Calculate Formula Used
Formula Used
B = μ₀I / (2πr) = B = μ₀I / (2πr)