How many centuries have there been til now?

As of 2023, there have been 21 centuries, starting from the 1st century (1 AD to 100 AD) and ending with the 21st century (2001 to 2100). Each century consists of 100 years, so the count progresses sequentially based on the passage of time. The current century, the 21st, began in the year 2001 and will conclude in 2100.