Memorizing a page of the Quran usually takes between 30 minutes to 2 hours. If you’re just starting, it might take closer to 1-2 hours because you’re learning how to do it. As you get better, you might remember the page in about 30-60 minutes.
Some people, who have lots of practice, can memorize a page in just 5-10 minutes. The time it takes depends on how you practice and how experienced you are. The key is to find a method that works best for you and stick with it.
