Football clubs are massive businesses. The top teams make millions every year through ticket sales, sponsorship deals, shirt sales and prize money. And with growing global fanbases and rising commercial income, the value of some clubs has reached eye-watering levels.

But one club is still much richer than all others, and it's worth more than Manchester City and Newcastle United combined. That club is Real Madrid. According to Forbes, the Spanish giants are now worth a staggering $6.75 billion (£5.3 billion), following a record-breaking season in which they earned more than $1.1 billion (£870 million) in revenue.

It's the fourth year in a row they've topped the global rankings.

Only one other sports team, the NFL's Dallas Cowboys, has ever crossed the $1 billion revenue mark in a single year. No other football club has come close.

Manchester United remain second on the list with a value of $6.6 billion (£5.21 billion), followed by Barcelona in third at $5.65 billion (£4.46 billion).

Manchester City are fifth, valued at $5.3 billion (£4.19 billion), while Newcastle United are down in 19th place with a value of $1.1 billion (£870 million).

Real Madrid's recent Champions League win helped boost their income, along with commercial deals and matchday earnings at their newly renovated Bernabéu Stadium, which cost around $1.9 billion (£1.5 billion) to upgrade.

The average value of the world's top 30 football clubs has also gone up, with all teams now worth a combined total of more than $72 billion (£53 billion).

Premier League clubs continue to dominate the list, with 8 English teams included in the top 20.

Other top clubs come from Spain, Germany, Italy, France and the United States.

Below is the list of the 20 richest football clubs in the world, along with their estimated value in US dollars and pounds.