How old was Isaac Newton when he died?

Isaac Newton was 84 years old when he died. He died in London in 1727 after a long life that transformed mathematics, physics, astronomy, and natural philosophy.

Newton was born in Woolsthorpe, Lincolnshire, on 25 December 1642 according to the Old Style calendar then used in England; this corresponds to 4 January 1643 in the Gregorian calendar. He died on 20 March 1727 under the Old Style calendar, or 31 March 1727 in the modern Gregorian calendar. Because of the calendar difference, some accounts display different dates, but his age is consistently given as 84.

Newton spent his final decades as Master of the Royal Mint and president of the Royal Society, as well as a celebrated scientific figure. He was buried in Westminster Abbey after a state funeral, an extraordinary honor for someone recognized primarily for intellectual achievement. His burial helped establish him as a national hero of science, not merely a Cambridge mathematician.