There's no magical age at which children should start to use the potty, but some develop the cognitive & physical skills to do so between 18 and 24 months of age.
It's really not a one-size-fits-all approach as many toddlers are ready to embark on this adventure by 2-2.5 years old while others show absolutely no interest until they are 3 or even 4 years old.
Before a baby's first birthday, though they may already begin to show interest in doing the toilet dance, bladder control isn't something they're up to achieving.
Even when a tot has mastered daytime dryness, keeping it in all night long should be seen as a separate potty-training milestone altogether.
Physical signs
- Can walk or even run independently.
- Urinates a fairly substantial amount at a time
- Has well-formed bowels at relatively predictable times
- Has had "dry" periods during the day, sometimes even during naptimes-this shows the bladder muscles has developed sufficiently
Behavioral signs
- Is able to sit for 2 - 5 minutes
- Is able to pull pants and underwear up and down.
- Seems uncomfortable when diaper is dirty/full
- Shows interest in the whole "going to the bathroom" process - wants to watch others and tries to mimic behavior.
- Can see either physically or verbally when a bowel movement is taking place (straining/grunting etc.)
- Communicates a desire to be independent
- Understand and takes pride in accomplishments
- Is in a cooperative, open state and has a positive attitude towards learning this new skill.
Cognitive signs
- Communicates well enough to understand the physical signs of needing to "go" and subsequently telling someone
- Is able to follow simple instructions when prompted.
- Can identify "pee" and "poo" and understands what these words mean.