There are some legal limits to how tall the fence can be in some places. So, you have to refer to your local laws before deciding the height of your fence. Apart from the legal side, the height of the fence should depend on what your intention for creating the fence is. If the fence is just for demarcating your land from your neighbours, then a two feet picket fence is sufficient. But some people want to keep other animals from getting inside their yard or to keep their cats or dogs from wandering outside of the yard. In that case, the fence should be one or two meters tall. However, there are some fixtures that you can install on the top of the fence to keep animals from getting out or getting in.