A Full Adder is a digital circuit that performs the addition of three binary inputs. In this tutorial, you will learn how this circuit works, its truth table, and how to implement one using logic gates.

## What is a Full Adder?

Adders can either be Half Adders or Full Adders. The difference is that the Half Adder is used to add only two 1-bit binary numbers, therefore its sum can only range from 0 to 2. To improve this performance, the Full Adder was developed. It is able to add three 1-bit binary numbers, achieving a sum range from 0 to 3, which can be expressed with two output bits (“11”).