It depends on what font type you use, where, and which unit.
In Braille, if you write like
█░ ██ █░ ░█ ██ █░ █░ █░ █░ ██
░█ ░█ ░█ █░ ██ ░░ ░░ ██ ░█ ░█
█░ █░ ░░ █░ █░ ██ ░░ █░ ░░ ░░
If you do it in a 22*3 square based grid which has the area of one squared,
the area of unshaded portion is 36/66 squared.