How do I tell my parents I do not agree with their opinion?

I make sure that my dad knows that I understand his opinion and where he is coming from. That way nothing can be blamed on ignorance. Then I tell him what I think, why I think this, and back up why I and do this. Then my father and I bat ideas back and forth in a calm matter. Staying calm is key.

Be polite but firm in your decision. Kindly voice your opinion to them without overpowering theirs.

You tell them you don't agree and explain why they'll understand it's not easy but you can do it.

Try and say it in a respectful way. Maybe starting off with "not to come off as rude..." Or something in the nature. They're your parents and will love you. Opinions are different with different people.

Tell them that you respect their opinion, but you have different viewpoints on the matter. Assert to them that you are entitled to your own opinion.

When we speak in a way that is peaceful and composed in the face of adversity, we raise ourselves above that adversity and, more often than people might expect, inspire others to do the same. Not only that, but by continuing to have our words come from a peaceful place, even in the face of others' anger or refusal to agree with us, we allow ourselves to be truly helpful to others and, as such, truly loving. By moving away from peacefulness, by choosing to communicate by shouting or insulting to get our points across, we move away from our ability to be truly loving, and are more likely to inspire a perpetuation of conflict and hurtfulness. Specifically, when we are called to communicate to someone that we don't agree with them, I've found that reminding them that their right to make their own choices in life is fully acknowledged and appreciated is always a helpful and compassionate thing to include at the start of the message, because chances are that the listener feels personally insulted by the speaker's disagreement. Now, the listener is encouraged to see the speaker's disagreement not as something to be feared or taken personally, but as a natural occurrence of life, as well as an opportunity for both people to become better educated on what is true about one another, which is always beneficial to one's life. Again, if one can not only accomplish all of that, but do so in a calm and loving way, even against the adversities of anger and resentment, then one has the potential to be truly inspiring to others, as they will become an example of wisdom, love, and the strength of will for all to live by.

The best way is to tell them honestly. I have always doubted my parents, I doubt that they care, I doubt that they love me at all, but as I grow I started realizing that yes, they do care and they do love me. Every parents want the best for their children, and I think it's perfectly okay not to agree with your parents' opinions sometimes. Rather than trying to cope with theirs, you should just tell them honestly. (in a polite way, of course)

You can just politely say: I disagree. Of course, that is just me and you may have a different opinion from me, yet I stand my ground. Allowing others to have their own opinion, but allowing yourself to have your own is always a good idea!

As I am speaking from my own experience, it is not easy to discuss with parents...strict ones especially. However, do try your best to explain your standpoint and explain where you are coming from and what it will mean to you if things go according to your plan.

It is normal to disagree other's opinions, but there is a proper way to go about doing so. For small, unimportant matters, it is best to not sweat it too much, however, if it is a bigger deal it is important to voice your concern. When doing so, ensure you are simply informing your parents of your concern with their belief. Be elaborative and respectful as you do not want to embarrass them, but you need to be informative enough so they may understand your reasoning without taking it as a personal attack.