Ncdu is a disk usage analyzer with an ncurses interface. It is designed to find space hogs on a remote server where you don’t have an entire graphical setup available, but it is a useful tool even on regular desktop systems. Ncdu aims to be fast, simple and easy to use, and should be able to run in any minimal POSIX-like environment with ncurses installed

Source: NCurses Disk Usage

On Ubuntu, it can be installed using APT

sudo apt-get install ncdu

On OS X, it can be installed using Homebrew:

brew install ncdu