Magnetic Field Calculator (Wire & Solenoid)
Compute the magnetic flux density around a long straight wire and inside an ideal solenoid from current, distance, turns and length.
How to Use the Magnetic Field Calculator (Wire & Solenoid)
- Enter current in amperes.
- Enter distance from the wire in centimetres (for wire field).
- Enter number of turns and solenoid length (for solenoid).
- Click Calculate.
Casi d'Uso
- •Coil design for electromagnets.
- •Physics homework.
- •Estimating stray fields in electronics.
Formula
Wire: B = μ₀·I / (2π·r). Solenoid: B = μ₀·n·I = μ₀·(N/L)·I. μ₀ = 4π × 10⁻⁷ T·m/A.
Domande Frequenti
Is the wire formula exact?
It assumes an infinitely long, thin, straight wire in vacuum. Close to finite wires it overestimates; through ferromagnetic cores it underestimates.
When does the solenoid formula hold?
It is the ideal-solenoid limit: long compared to its diameter, tightly wound, infinite coil. Real coils show end-field drop-off.