For the Christmas and New Year's Day holidays, orders placed after 1:00PM EST on Friday, 12/21 will be shipped on Wednesday, 12/26. Orders placed after 1:00PM EST on Friday, 12/28 will be shipped on Wednesday, 1/2/19.

UPS and USPS do not guarantee delivery times through the end of the year. This may include an extra day in ground shipping and later delivery for overnight services.

Canada: Postal shipping delays are possible from the Canada Post strike.
We are now required to collect sales tax in several states. If your business is tax exempt, learn more here.
All orders placed & paid online by 1PM ET (M-F) will be shipped the same day!
The K&J Magnetic Gap Calculator

Select Configuration:
Two Disc Magnets
Two Disc Magnets with Yoke
Two Disc Magnets with Yoke & Iron Cones


This Gap Calculator estimates the magnetic field strength between two neodymium magnets separated by a small gap.

The magnets are positioned with opposite poles facing one another, so that the magnets are attracting towards one another.

For an in-depth explanation of how this calculator works, read our Gap Calculator blog article here.

All data is provided in gauss.

Click here to go to our Original Magnet Calculator that shows Pull Force and more.

All data presented in this calculator is derived from a series of finite element analysis studies for a pair of equal sized disc/cylinder magnets 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.  Nearby magnets or ferromagnetic materials can 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 clyindrical 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:


10% Off
Our Popular Deluxe Magnet Kit

An attractive holiday gift for your favorite magnet enthusiast.

10% Off
Magnetic Thumbtacks

10% Off

Magnetic Hook
Great for holding a wreath to a steel door!

Order by phone:
or 215-766-8055

Order online for
fastest shipping!

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