You can use both will and going to to make predictions.
For example, "I think the Labour party will lose the next election." Or "I think the Labour party are going to lose the next election."
If you can make a prediction based on what you see now, we use going to.
For example, "You're driving too fast, you're going to hit the car in front!"
Grammar and Tenses
Future plans and arrangements
If something has already been planned, use going to with the verb, or the Present Continuous tense.
"I'm going to take my exams next month."
"He's visiting a client on Tuesday."
Grammar and Tenses
Unplanned future
When we decide to do something at the moment of speaking, we use will.
"The phone's ringing - I'll answer it."
(You only answer the phone when it starts ringing.)
Grammar and Tenses
Future schedules
When we want to talk about a schedule, we use the Present Simple tense.
"The plane leaves in half an hour - we'd better hurry."
"Next week I fly to Italy, then on Tuesday, I'm in Spain."
Grammar and Tenses
Events in progress at a time in the future
To talk about something that will be in progress at a time in the future, use will be doing.
"For example, "This time next week, I'll be sitting on a plane."
We can also use this form to make polite requests.
Grammar and Tenses
"Will you be using the car tomorrow?"
(If you won't, can I use it?)
Grammar and Tenses
Events that will be completed by a time in the future
If you want to say that something will be completed by a time in the future, use will have done.
"I'll have finished the report by this afternoon."
Grammar and Tenses
Final tip
Many learners of English overuse will and going to. Try using all the different future forms so that you become more confident.