Hi there,
This can be very broad as it will vary from student to student and uni to uni. Generally you'll have a lot of basic free time outside of lectures. Some courses have one or a few lectures every day while others may give you one or two days totally free. I would say in this sense its going to feel like you have a lot.
However you need to make sure you consider your time to study, complete projects and generally look over your work independently. I would recommend for every hour in lecture , you spend an hour studying the learnt material. The time for a project will vary for every project and you may need to focus a lot into them.
As well you'll want to join some clubs and societies! This really isn't too bad to do at all and the times are usually outside of lecture times so you don't worry about clashing. As long as you're doing regular work then having time for hobbies is absolutely fine.
Generally you'll have a good amount of free time provided you are steady with your work. If you spend very little time working one week you may find you have no free time the next when the deadlines due so just be careful with how you utilise your time.
Hope this helped,
- Sophie (uni of Bath)