This template is used on 3300 pages, and changes to it will be widely noticed. Please test any changes in the template's /sandbox or /testcases subpages, or in a user subpage, and consider discussing changes at the talk page before implementing them.
{{Age in years|2000}} yields 24–25.
{{Age in years|1900|1950}} yields 49–50.
Note that the template provides an age range: during the year 2015, someone born in 2000 is either 14 or 15 years old, depending on whether they have passed their birth date in the later year.
{{Birth based on age as of date}} – displays approximate birth year and current age; used when a dated reference mentions the age of a person as of the date of publication
{{Birth date based on age at death}} – displays approximate birth year based on age at death (useful if exact birth date is not known, but age at death is)
{{Death date}} – displays the date and related hidden metadata