We celebrate our birthdays on the same date each year, but alongside our chronological age – the number of years we’ve been alive – we also have a biological age that reflects how quickly our bodies are succumbing to wear and tear.

Working out someone’s biological age is more difficult than counting backward to a date of birth, though we are getting better at it.

Knowing this information can help in a variety of ways when it comes to health, including spotting serious problems earlier on.