For the Memorial Day holiday, orders placed after 1:00PM EDT on Friday, 05/24/2024, will be shipped on Tuesday, 05/28/2024.        
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Magnetic Field Calculator

Calculate magnetic field of magnets in free space

Measurement Position:
(If unsure, leave blank.)

Results units

* Note that the Measurement Position assumes the zero position (0,0) is at the center of the magnet, inside the magnet.

All data presented in this calculator is derived from a series of finite element analysis studies for a single magnet in free space.  While we have verified the accuracy of results with our own experimental measurements, be sure to verify with your own measurements in your particular application.  Other nearby magnets or ferromagnetic materials can dramatically alter your results.

All dimensions and positions must be in decimal format. Fractional inches will not calculate correctly.

This calculator only considers discs and cylinders that are magnetized along the cylindrical axis. While K&J Magnetics offers diametrically magnetized magnets, this calculator does not apply to them.

This calculator is currently a beta version and is intended only for reference. K&J Magnetics, Inc. will not be held liable for its use. All calculations are approximations and should not be used as the sole source of design data. The factors of your application may change these values considerably. Be sure to test magnets in your configuration.

Please report any troubles, concerns or suggestions about this calculator to:


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5/8" dia x 1/4" thick

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1/4" OD x 1/8" ID x 1/4" thick ring

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Magnetic badge holder and name tag

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1" x 3/8" x 3/8" block, 22 lb pull force

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K&J Magnetics, Inc.
Your online source for incredibly powerful neodymium magnets.