The universe began with the Big Bang approximately 13.787 billion years ago. Scientists determined this age by measuring the cosmic microwave background radiation — the afterglow of the Big Bang — with the Planck satellite. The universe's age is not a fixed number: it increases by exactly one year every year, one second every second.
The Cosmic Dashboard displays the universe's age to six decimal places, updating every 100 milliseconds. This lets you watch cosmic time flow in real time, though each visual update corresponds to only a tiny fraction of a year on the universe's timescale. The age is calculated as: 13.8 billion + (time elapsed since January 1, 2020 UTC) in years.
For scale: the universe is 13.8 billion years old. The Milky Way formed 13.6 billion years ago (98.5% of the universe's age). Our Solar System formed 4.6 billion years ago. Complex life appeared 600 million years ago. A human lifetime of 80 years is 0.00000058% of the universe's age.