This page lists examples of magnetic induction B in teslas and gauss produced by various sources, grouped by orders of magnitude.
The magnetic flux density does not measure how strong a magnetic field is, but only how strong the magnetic flux is in a given point or at a given distance (usually right above the magnet's surface). For the intrinsic order of magnitude of magnetic fields, see: Orders of magnitude (magnetic moment).
Note:
These examples attempt to make the measuring point clear, usually the surface of the item mentioned.
| Factor (tesla) | SI name | SI Value | CGS Value | Example of magnetic field strength |
|---|---|---|---|---|
| 10−18 T | attotesla | 1 aT | 10 fG | |
| 5 aT | 50 fG | Sensitivity of Gravity Probe B gyroscope's "SQUID" magnetometer (most sensitive when averaged over days) [3] | ||
| 10−17 T | 10 aT | 100 fG | ||
| 10−16 T | 100 aT | 1 pG | ||
| 10−15 T | femtotesla | 1 fT | 10 pG | |
| 2 fT | 20 pG | |||
| 10−14 T | 10 fT | 100 pG | ||
| 10−13 T | 100 fT | 1 nG | Human brain | |
| 10−12 T | picotesla | 1 pT | 10 nG | |
| 10−11 T | 10 pT | 100 nG | "Potholes" in the magnetic field found in the heliosheath around the Solar System reported by Voyager 1 (NASA, 2006) [4] | |
| 10−10 T | 100 pT | 1 μG | Heliosphere | |
| 10−9 T | nanotesla | 1 nT | 10 μG | |
| 10−8 T | 10 nT | 100 μG | ||
| 10−7 T | 100 nT | 1 mG | Coffeemaker (30 cm or 1 ft away) [5] | |
| 100 nT to 500 nT | 1 mG to 5 mG | Residential electric distribution lines (34.5 kV) (15 m or 49 ft away) [5] [6] | ||
| 10−6 T | microtesla | 1 μT | 10 mG | Blender (30 cm or 1 ft away) [5] |
| 1.3 μT to 2.7 μT | 13 mG to 27 mG | High power (500 kV) transmission lines (30 m or 100 ft away) [6] | ||
| 6 μT | 60 mG | Microwave oven (30 cm or 1 ft away) [5] | ||
| 10−5 T | 10 μT | 100 mG | ||
| 24 μT | 240 mG | Magnetic tape near tape head | ||
| 31 μT | 310 mG | Earth's magnetic field at 0° latitude (on the equator) | ||
| 58 μT | 580 mG | Earth's magnetic field at 50° latitude | ||
| 10−4 T | 100 μT | 1 G | Magnetic flux density that will induce an electromotive force of 10−8 volts in each centimeter of a wire moving perpendicularly at 1 centimeter/ second by definition (1 gauss = 1 maxwell /centimeter²) [7] | |
| 500 μT | 5 G | Suggested exposure limit for cardiac pacemakers by American Conference of Governmental Industrial Hygienists (ACGIH) | ||
| 10−3 T | millitesla | 1 mT | 10 G | Refrigerator magnets (10 G [8] to 100 G [9] ) |
| 10−2 T | centitesla | 10 mT | 100 G | |
| 30 mT | 300 G | Penny-sized ferrite magnet | ||
| 10−1 T | decitesla | 100 mT | 1 kG | Penny-sized neodymium magnet |
| 150 mT | 1.5 kG | Sunspot | ||
| 100 T | tesla | 1 T | 10 kG | Inside the core of a 60 Hz power transformer (1 T to 2 Tas of 2001 [update] ) [10] [11] or voice coil gap of a loudspeaker magnet (1 T to 2.4 Tas of 2006 [update] ) [12] |
| 1.5 T to 7 T | 15 kG to 70 kG | Medical magnetic resonance imaging systems (in practice) [13] [14] [15] | ||
| 9.4 T | 94 kG | Experimental magnetic resonance imaging systems: NMR spectrometer at 400 MHz (9.4 T) to 500 MHz (11.7 T) | ||
| 101 T | decatesla | 10 T | 100 kG | |
| 11.7 T | 117 kG | |||
| 16 T | 160 kG | Levitate a frog by distorting its atomic orbitals [16] | ||
| 23.5 T | 235 kG | 1 GHz NMR spectrometer [17] | ||
| 32 T | 320 kG | Strongest continuous magnet field produced by all-superconducting magnet [18] [19] | ||
| 38 T | 380 kG | Strongest continuous magnetic field produced by non-superconductive resistive magnet [20] | ||
| 45.22 T | 452.2 kG | Strongest non-tiny continuous magnetic field produced in a laboratory (Steady High Magnetic Field Facility (SHMFF) in Hefei, China, 2022), [21] beating previous 45 T record (National High Magnetic Field Laboratory's FSU, USA, 1999) [22] (both are hybrid magnets, combining a superconducting magnet with a resistive magnet) | ||
| 45.5 T | 455 kG | Strongest continuous magnetic field produced in a laboratory (National High Magnetic Field Laboratory's FSU, USA, 2019), though the magnet is tiny (only 390 grams) [23] | ||
| 102 T | hectotesla | 100 T | 1 MG | Strongest pulsed non-destructive ("multi-shot") magnetic field produced in a laboratory (Pulsed Field Facility at National High Magnetic Field Laboratory's Los Alamos National Laboratory, Los Alamos, NM, USA) [24] |
| 103 T | kilotesla | 1 kT | 10 MG | |
| 1.2 kT | 12 MG | Record for indoor pulsed magnetic field, (University of Tokyo, 2018) [25] | ||
| 2.8 kT | 28 MG | Record for human produced, pulsed magnetic field, (VNIIEF, 2001) [26] | ||
| 104 T | 10 kT | 100 MG | ||
| 35 kT | 350 MG | Felt by valence electrons in a xenon atom due to the spin–orbit effect [27] | ||
| 105 T | 100 kT | 1 GG | Non-magnetar neutron stars [28] | |
| 106 T | megatesla | 1 MT | 10 GG | |
| 107 T | 10 MT | 100 GG | ||
| 108 T | 100 MT | 1 TG | ||
| 109 T | gigatesla | 1 GT | 10 TG | Schwinger limit (~4.41 GT) above which the electromagnetic field becomes nonlinear |
| 1.6 GT | 16 TG | Swift J0243.6+6124 most magnetic pulsar [29] [30] | ||
| 1010 T | 10 GT | 100 TG | Magnetar neutron stars [31] | |
| 1011 T | 100 GT | 1 PG | ||
| 1012 T | teratesla | 1 TT | 10 PG | |
| 1013 T | 10 TT | 100 PG | ||
| 1014 T | 100 TT | 1 EG | Magnetic fields inside heavy ion collisions at RHIC [32] [33] |
[T]he pizza-shaped refrigerator magnet you got from your local pizzeria is 10 gauss
A refrigerator magnet is 100 gauss, a strong refrigerator magnet.
A modern well-designed 60 Hz power transformer will probably have a magnetic flux density between 1 and 2 T inside the core.
Typical flux densities for (half decent) loudspeakers range from around 1 Tesla (10,000 Gauss) up to around 2.4T, and I would suggest that anything less than 1T is next to useless. Very few drivers use magnetic materials that will provide much more than 1.8T across the gap...
