At what age should I start allowing my children to make their own decisions?

I think it is important to allow your teenager to make their own decision, how else will they learn from their mistakes. However it is important to have stay as parent when it comes to their health and safety.

you can permit your children to make their own decisions  at the adolescence age but  you must except or post ponied some of these decisions.    

As long as the children can decide what is really good for them with the supervision of their parents. It does not need a child to be young or older, they will always need their parents in every decision they will do.

Around the age of 14, as it is when  they are in their teens

at the age of 7, children start to build their own understanding of their surroundings. At this stage, they should be given the right and chance to make their own decisions to develop their autonomy

Since the early years of the child's age with the follow-up and parental guidance

From birth everyone should be allowed and encouraged to practice decision making.

At the age of 18 and must always keep tabs

after 18 years children may get decisions 

I can say from their year one, starting with simple decisions, when introducing how they would take decision and why they selected that, this will build up their own character.

If it is possible from the earliest age, guide them if possible and allow them to take decisions for their own.

I think that after 14 years age we should provide space to child that he/she can take decision but parents responsbility is that if their child take good decision they support and if their child get mistake they suggest them. It would be very good option.