What Is the Strength of Two Magnets Together?

Iron filings trapped between two magnets.
••• Jupiterimages/Photos.com/Getty Images

Magnets can be combined to either reduce or increase their strength, depending on their orientation to each other. Combining two equal magnets will not double their strength, but it will come close.

Combining N-to-S

If the north side of one magnet is combined with the south side of the other, so that the poles are oriented N-S-N-S, then the strength will be close to double that of a single magnet, if they are the same shape and strength.

Less Than Double

The reason it won’t precisely double is because the magnets don’t occupy the same space. Although the field strengths are additive, the field strength on the top surface of the combined magnet is a distance away from the other magnet--namely, the width of the top magnet away--so the full effect of the bottom magnet isn’t felt.

Combining N-N

If the two magnets are combined so the same poles are facing, then their magnetic strength will be greatly reduced. They will not be completely canceled out, by the same argument as above: they don’t occupy the same space.


A student might expect that combined magnets would cancel, like electric charges. But magnetic fields are instead additive.


Note that magnetism can be viewed, loosely, as created by the circles that electrons make in their orbits. If the orientation of these orbits is random, they’ll cancel each other. If they’re all oriented in the same direction, their effect is cumulative and the field strength is additive.

Related Articles

What Happens When You Cut a Bar Magnet in Half?
What Are 3 Similarities Between Magnets and Electricity?
What Is the Difference Between Electronic Geometry...
Science Facts About Magnets for Kids
What Are Bar Magnets Used For?
How to Build a Super Magnet
Quick & Easy Experiments With Magnets
What Causes Things to Get Magnetized?
Magnetic Levitation Projects for Kids
How Does Heat Affect Magnets?
How to Make a Homemade Magnetic Levitation
Types of Magnets
What Types of Metal are Attracted to Magnets?
How Does a Magnet Lose Its Magnetism?
What Causes a Permanent Magnet to Lose Its Magnetism?
What Makes a Material Magnetic?
Properties of Magnets & Electromagnets
The Uses of Different Shaped Magnets
Why Magnets Have No Effects on Some Metals