Magnetic Field Strength Converters | Amperes per Meter & Oersteds Hub
Magnetic Field Strength Converter (Amperes per Meter to Oersteds)
Welcome to ConverterHub’s complete Magnetic Field Strength Converters directory. Convert effortlessly across International System (SI) and CGS-Gaussian electromagnetic units—including Amperes per meter (A/m), Kiloamperes per meter (kA/m), and Oersteds (Oe)—with exact physical magnetizing field formulas, interactive tools, Biot-Savart and Ampere’s circuital law guidelines, permanent magnet coercivity references, and authoritative physics benchmark tables.
All Magnetic Field Strength Conversion Tools
Select any magnetic field strength conversion tool below for instant calculations, step-by-step mathematical derivations, and technical reference tables:
Amperes per Meter & Oersteds
Understanding Magnetic Field Strength (H) vs. Magnetic Flux Density (B)
In classical electrodynamics, two distinct quantities describe magnetic phenomena:
- Magnetic Field Strength (H): Also called the auxiliary magnetic field, magnetic field intensity, or magnetizing field. Measured in amperes per meter (A/m) in the SI system and oersteds (Oe) in the CGS-Gaussian system. According to Ampere’s circuital law,
∮ H · dl = I_free, meaning H depends exclusively on macroscopic free electrical currents, independent of the magnetic material’s atomic response. - Magnetic Flux Density (B): Also called magnetic induction or the fundamental magnetic field. Measured in teslas (T) or gauss (G). It measures the physical force exerted on moving charges via the Lorentz force law (
F = q(v × B)). - The Constitutive Relationship: The two fields are linked by the material’s magnetic permeability:
B = μ · H = μ₀(H + M), whereμ₀ = 4π × 10⁻⁷ H/mis the magnetic vacuum permeability andMis the material’s magnetization. In free space (vacuum),B = μ₀ H. In CGS-Gaussian units,μ₀ = 1, which historically caused 1 Oersted of field strength in vacuum to correspond to 1 Gauss of magnetic flux density.
The SI to CGS-Gaussian Conversion Ratio
The relationship between the SI unit (A/m) and the Gaussian unit (Oe) stems directly from the definition of the Biot-Savart law and Ampere’s constant:
1 Oersted (Oe) = 1,000 / (4π) A/m ≈ 79.5774715 A/m ≈ 79.5775 A/m1 Ampere per meter (A/m) = 4π / 1,000 Oe ≈ 0.01256637 Oe1 Kiloampere per meter (kA/m) = 1,000 A/m = 10⁴ / (4π) Oe ≈ 12.56637 Oe
Magnetic Field Strength Benchmarks in Science & Engineering
Magnetic field strength values across natural phenomena, electronic hardware, and medical equipment:
| Magnetic System / Phenomenon | Field Strength in A/m | Field Strength in Oe | Engineering Context |
|---|---|---|---|
| Earth’s Geomagnetic Field (Surface) | ~24 to 48 A/m | ~0.3 to 0.6 Oe | Planetary geomagnetic shielding |
| Magnetic Audio Recording Tape Bias | ~20 to 40 kA/m | ~250 to 500 Oe | AC bias field in analog tape heads |
| Alnico Magnet Coercivity (Hc) | ~48 kA/m | ~600 Oe | Demagnetization resistance threshold |
| Ceramic Ferrite Magnet Coercivity (Hc) | ~240 kA/m | ~3,000 Oe | Permanent magnet motor stator poles |
| Neodymium (NdFeB) Magnet Coercivity (Hcj) | ~955 to 2,390 kA/m | ~12,000 to 30,000 Oe | Ultra-high performance rare-earth magnets |
| 1.5T MRI Scanner Bore (in vacuum) | ~1.19 × 10⁶ A/m | ~15,000 Oe | Diagnostic superconductive clinical scanner |
| 3.0T MRI Scanner Bore (in vacuum) | ~2.39 × 10⁶ A/m | ~30,000 Oe | High-resolution neuroimaging magnet |
Summary of Exact Conversion Formulas
Use these reference formulas for all manual or automated magnetic field calculations:
- A/m to Oe:
Oe = (A/m) / 79.5775 = (A/m) × 0.01256637 - Oe to A/m:
A/m = Oe × 79.5775 - A/m to kA/m:
kA/m = (A/m) / 1,000 - kA/m to A/m:
A/m = kA/m × 1,000 - kA/m to Oe:
Oe = kA/m × 12.56637 - Oe to kA/m:
kA/m = Oe × 0.0795775