Toddlers wear size 5 diapers for around 5 months to 6 months.
When toddlers are in size 5 diapers, most toddlers wear the size 5 diapers from around 18 months of age to up to 3 years old, although some toddlers may wear size 5 diapers until as old as 4 years old depending on their growth weight and build.
Size 5 diapers are designed for toddlers weighing 27 lbs and up.
Many parents also find that they use less size 5 diapers than the smaller sizes of diapers, because they also often switch to training paints or underwear as their child learns to use the toilet, which is often between the ages of 2 and 3.5 years old.
Size 5 diapers are for when your toddler is over 27 lbs of weight an if the fastening tapes are struggling to reach the landing zone or there are marks that appear on your toddlers thighs or you have any regular frequent blowouts or leaking that occurs especially at night, then it's time to move up to a size 5 from a size 4.
Or if they are already in a size 5 diaper, then it's time to move to a size 6.
Size 4 diapers are for ages 18 months old to as old as 36 months or 3 years.
However the actual age that a toddler or child would wear size 4 diapers also depends on the child's build and their weight.
Size 4 diapers though are designed to fit children and toddlers weighing between 22 lbs to 37 lbs.
But weight alone cannot always determine the fit of the diaper or how long the toddler or kid will stay in the diaper size.
Some 2 year old's may need a size 5 diaper and some may even fit into a size 3 diaper in some cases.
And then some 2 and 3 year old's may need a size 5 diaper depending on how they are built.
Size 4 diapers are often worn during a toddlers active phase when they are moving, walking and even sometimes even beginning potty training.
Some toddlers stay in a size 4 diaper until they are potty trained at or before 3 years old and some toddlers may need to move up to a size 5 diaper before age 3 and stay in a size 5 diaper until age 3 or a bit over until they are potty trained.
Most toddlers and kids finish their diapering in a size 4 or 5 at most before they are potty trained.
Size 6 diapers are still needed by some kids and even size 7 diapers, but size 6 or size 7 diapers are the least needed diaper sizes.
Also diapers can also fit different even if they are listed as being the same size as some brans of diapers run smaller than others and some brands of diapers run larger than others in the same size.
If the diapers are leaking constantly, leaving red marks on the child's waist or thighs, or if the diapers fastening tabs can't reach the center of the diaper any longer, then it's time to move to a larger size diaper.
Size 4 diapers are often used for a long period of time and sometimes children stay in a size 4 diaper from 12 months to 18 months or longer, depending on your child's growth rate.
And some kids might need a slightly bigger diaper to hold more pee, if they are a heavy wetter, even if the size 4 diaper is fitting them properly.
Larger size diapers have more absorbent material and can hold more pee, but you also need to make sure that the diaper is not too big as any gaps in the legs or too much sagging can lead to leaks of pee and poop.