Harry Potter’s parents were killed when he was one-year old and he lived with his (muggle) aunt and uncle for ten years, so it came as a big surprise to him – as well as readers and viewers – that his parents left him a lot of money, but how much was it? Back in 1997, J.K. Rowling introduced readers to the Wizarding World through the story of “the boy who lived” in Harry Potter and the Philosopher’s Stone, the first in what would become a series of seven novels, which came to an end in 2007 with Harry Potter and the Deathly Hallows.
Harry Potter and company made the jump to the big screen in 2001, with the final book being split into two films. The Harry Potter film saga brought the Wizarding World to a wider audience, further expanding the books’ fanbase and also making some questions left by the novels even bigger. In Harry Potter and the Philosopher’s Stone, the audience learned that Harry wouldn’t have to worry about paying for his school supplies and more as his parents left him a “small fortune” in vault 687 of Gringotts Wizarding Bank, but how much money was there?
When Hagrid took Harry to Gringotts when shopping at Diagon Alley for school supplies, it was revealed that the vault was full of galleons, and that he would never have to worry about not having enough money for books, clothes, and other expenses as he was more than covered. This, of course, has made fans wonder how James and Lily (who were only 21-years old when they were killed) were able to leave so much money to Harry, and the answer can be found a few generations back in the Potter family tree.
In an entry on Wizarding World (formerly Pottermore), Rowling explained how the Potters left such a big amount of money to their son, and it’s all thanks to Linfred of Stinchcombe. An eccentric though well-beloved man, he was nicknamed “the Potterer”, which then transformed into “Potter”, and his muggle neighbors often called upon his medicinal services. All his experiments led him to create numerous remedies that evolved into potions “still used to this day”, among those Skele-gro (the one Madame Pomfrey gave Harry to regrow his arm bones) and Pepperup Potion, which laid the foundation of the Potter family’s fortune.
Each Potter family member continued to work to maintain the family’s fortune, but it was Fleamont Potter (Harry’s grandfather) who “took the family gold and quadrupled it” by creating Sleekeazy's Hair Potion. As for how much money Harry had, some fans have tried to calculate it by how many galleons are shown in the movie, and taking into account that one galleon is worth $6 USD, Harry’s fortune at the beginning of the series was around $303,750. It’s worth noting that, following Sirius Black’s death, Harry inherited the remainder of his wealth in gold (as he was disowned when he was 16), so he got some extra money after Harry Potter and the Order of the Phoenix.
The money Harry Potter inherited was enough for him to not worry about it during his school years, but he obviously had to work after that to maintain the family’s fortune and make sure his children were covered too, which he surely achieved after the events of the Harry Potter series.