The age that a child should be able to tie their shoes is by age 5 to 6 years of age.
Although some kids may master tying their shoes earlier or later.
However by age 5 or 6 most kids should be able to tie their shoes on their own pretty good although some may need a little help.
Age 5 and 6 is when most kids develop the fine motor skills and coordination required to tie their shoes.
Every child also develops at their own pace and some children may take longer to master the skill of tying their shoes than others and the same goes with learning other things.
Tying your shoes requires the development of fine motor skills which include hand eye coordination, dexterity as well as the ability to manipulate objects using both hands.
It's recommended that you introduce the concept of tying shoes around age 5 which is when children are developing these fine motor skills.
Learning to tie ones shoes also takes time and practice and patience so you should also be patient and encourage the child to keep trying.
For children struggling to tie their shoes or for children below 5 years old using slip on shoes or Velcro shoes are a good option where they can put the shoes on themselves easier.
I learned to tie my shoes by age 5 but it took until 6 until I was more able to tie my shoes without issues and even by 6 I sometimes had trouble untying my shoes and would sometimes struggle with having knots in my shoelaces.