While the conversation will most likely be difficult, delivering the news of your divorce to your children is also an opportunity to remind them that they are your  priority, that you love them, and that as a family you’re going to always work together to meet their needs. Above all, it is vital to be  certain that the divorce will  happen before you tell your kids. 

Next, consider the following guidelines:

1. Come to an agreement with your former spouse about the discussion you will have with your children. Although your marriage may be irretrievably broken, your love and responsibility for your kids is not. Having a conversation before the discussion with your kids will help you avoid hashing out your differences in front of your children, which isn’t fair to them. If you feel like the two of you are unable to communicate rationally, consider hiring a counselor or mediator to assist with the conversation.
2. Remain calm and avoid finger pointing. Children already have a natural tendency to blame themselves for something that goes wrong in a family. The manner in which you and your former spouse present divorce news to your kids can either reduce or increase their anxiety. It also helps them anticipate the most positive outcome for themselves. If the discussion becomes a blaming and screaming match, your kids will feel confused and unsettled about what is happening. Instead, avoid talk about whose “fault” this is. 
3. Provide a general “why” answer, but avoid additional specifics. It is not necessary or even appropriate that you provide your kids with specific details about what led to your divorce decision. However, they will naturally want to know why it is happening. Older children will understand that this is a massive life shift. They will likely weigh that shift against the reasons you provide to them. So while it’s best to avoid sharing details of a personal nature, you’ll want to be prepared to give them some  general explanation. 
4. Welcome, their questions as they arise. In the initial conversation, they’re likely to ask about where the departing parent will be living, how often they will get to see that parent, if they’ll have a choice in which parent to live with and other questions. To the best of your ability, be open and honest in your responses. If you don’t know the answer to the question, tell your children that you don’t know. As the conversation unfolds, they are likely to revisit the issue on several occasions to ask questions that have come to mind. Remember to be patient and continue to answer the questions as best as you can. It may take some time for them to articulate their feelings.