Magnetic Flux Density (B

Magnetic Flux Density (B), Tesla, Gauss & Energy Density Metrology

Magnetic Flux Density (B, also referred to as magnetic induction or magnetic B-field) measures the strength and concentration of magnetic flux per unit area:

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• Universal Magnetic Flux Density Conversion Formulas (SI & CGS)**:

1 Tesla (T) = 10,000 Gauss (G) = 10 kG = 1,000 mT = 10^6\ μT = 10^9 nT

1 Gauss (G) = 10^-4 Tesla (T) = 0.10 mT = 100\ μT = 1,000 mG = 100,000 nT

1 Microtesla (μT) = 0.010 Gauss = 10 mG = 1,000 nT | 1 Gamma (γ) 1 nT = 10^-5 G

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• Magnetic Energy Density & Lorentz Force Equations**:

u_m = (B^2) / (2μ_0)

F = q v B θ (Lorentz Force on a Moving Charge in Newtons, N)

Φ = B A θ (Total Enclosed Magnetic Flux in Webers, Wb)

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• Standard Magnetic Induction Benchmarks**:

• Earth Geomagnetic Surface Field: 50.0\ μT = 0.50 Gauss = 500 mG Planetary magnetic shielding

• Ceramic Refrigerator Magnet: 10.0 mT = 100.0 Gauss Consumer ferrite magnet

• NdFeB N52 Neodymium Magnet: 1.45 Tesla = 14,500 Gauss = 14.5 kG High-energy rare-earth

• Clinical 1.5T MRI Scanner Bore: 1.50 Tesla = 15,000 Gauss u_m = 895.2 kJ/m^3

• High-Field Hybrid Magnet: 45.0 Tesla = 450,000 Gauss u_m = 805.7 MJ/m^3

How to Use This Calculator

Enter your Magnetic Flux Density (B / Induction) (e.g. 1.5 in B), From Flux Density Unit — choose from Tesla (T = Wb/m² = N/(A·m) - SI Standard), Gauss (G = 10⁻⁴ T = 100 µT - CGS Unit), Millitesla (mT = 10⁻³ T = 10 Gauss), To Flux Density Unit — choose from Gauss (G), Tesla (T), Millitesla (mT), Surface Probe Area (A in cm²) (e.g. 100.0 in cm²), and Magnetic Induction Benchmark — choose from Custom Flux Density, Earth Geomagnetic Surface Field (50.0 µT = 0.50 Gauss = 500 mG), Ceramic Refrigerator Magnet (10.0 mT = 100.0 Gauss). Results update instantly as you type — adjust any value to compare scenarios.

The Formula

Magnetic Field Energy Density: u = B^2 / (2 * mu_0) in J/m^3

Enclosed Magnetic Flux: Phi = B * Area (Webers)

Worked Example

A biomedical engineer converts an MRI fringe field safety boundary of 5.0 Gauss into 0.50 Millitesla (500 µT) to mark the five-gauss line beyond which pacemakers and ferromagnetic tools are prohibited.

Understanding Your Result

Unit conversions are exact by definition within a given measurement system (e.g., 1 km = exactly 1,000 m). Cross-system conversions (metric to imperial) use defined exchange factors: 1 inch = exactly 2.54 cm; 1 pound = 0.45359237 kg. Round your converted result to match the precision of your original measurement — expressing more decimal places than your input justifies implies false accuracy. For regulatory, legal, or safety-critical applications, verify which measurement system is required by the applicable standard.