It takes around 10 minutes to mine a single Bitcoin. However, the time taken can vary drastically depending on the mining difficulty and the number of miners. For instance, when Bitcoin first launched in 2009, it took less than a minute to mine a block.
As more miners joined the network and competition increased, the average time to mine a block rose to 10 minutes. Today, there are over 12 million actively mining Bitcoin rigs competing for rewards. The total hash rate currently stands at around 1018 hashes per second – that's over 1 quintillion calculations per second! Needless to say, it's not easy to earn a Bitcoin these days.