Prince William
Prince William and Prince Harry's net worth is $40 million, but the Duke of Cambridge will become $20 million richer when Prince Charles becomes king. Pictured: Prince William and Prince Harry attend the European Premiere of 'Star Wars: The Last Jedi' at Royal Albert Hall on Dec. 12, 2017 in London. Getty Images/Eddie Mulholland

Prince William and Prince Harry are said to have a net worth of $40 million, but where does their fortune come from?

According to Town & Country, the Duke of Cambridge and Duke of Sussex received roughly $89 million from a trust fund commissioned by the Queen Mother. Prince Harry will receive most of the cash as Prince William will have more fortune when he takes over the throne.

"Princes William and Harry will reportedly share about £14 m from the estate of their late great-grandmother," BBC reported. "The bulk of the cash will go to the younger brother, since William will benefit financially by becoming king."

Aside from the trust fund from the Queen Mother, Prince William and Prince Harry received a small fortune from their late mom, Princess Diana. In 2012, Middleton's husband inherited half of their mother's estate which was roughly $17 million. Prince Harry received the same amount when he turned 30.

In addition, Prince William made $60,000 a year as an air ambulance pilot. Prior to that, Prince William also served in the military. When he became a helicopter pilot in the RAF Search and Rescue Force, he received between $68,000 and $74,000. He left the role in 2013.

Celebrity Net Worth stated that the biggest income and net worth of Prince William come from the Duchy of Cornwall. At the time, Prince Charles is running it and it pays for the royal brothers' living expenses, travel, staff and wardrobe.

Prince William will be a whole lot wealthier than Prince Harry when Prince Charles becomes king because he will take over The Duchy. It is estimated that the Duke of Cambridge will become $20 million richer.

In related news, Prince William inherited Princess Diana's penchant for Cartier watches. When their mother passed away, the dukes were allowed to take a piece of jewelry from her collection. Prince William took her mom's Cartier watch. When Prince William and Middleton celebrated their third anniversary, the duke purchased a Ballon Bleu de Cartier watch worth $7,650 for his wife.

On the other hand, Prince Harry opted for Princess Diana's sapphire and diamond engagement ring. The ring ended up in Middleton's hands as Prince William used it when he proposed to the Duchess of Cambridge. The brothers reportedly agreed that whoever between them proposes first will use it.