Truth table for a NAND gate
Input AInput BOutput

A NAND gate (sometimes referred to by its extended name, Negated AND gate) is a digital logic gate with two or more inputs and one output with behavior that is the opposite of an AND gate. The output of a NAND gate is true when one or more, but not all, of its inputs are false. If all of a NAND gate's inputs are true, then the output of the NAND gate is false.

The truth table for a NAND gate with two inputs appears to the right.


Each of the symbols below can be used to represent a NAND gate. There are multiple international stnandards defined, and one may preferred over the other in your region of the world.

ANSI / IEEE NAND Gate symbol IEC NAND Gate symbol

Live Example

Try the following interactive example to see for yourself how a NAND gate behaves.

Please ensure that Adobe Flash Player 10.2 or greater is installed.

Further Reading

To learn more, check out the following external resources:

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