A Sim can go through life starting as a baby, toddler, child, teen, young adult (if you have University), adult, and elder. During their life they can also experience pregnancy, death, and taxes (yes Sims do pay property tax when they pay their bills);
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Babies = 3 days






Toddlers = 4 days






Children = 8 days






Teens = 15 days






Young adults = 24 days (University only)






Adults = 30 days






Elder = Varies; depends on their aspiration levels, etc.
 A huge responsibility of playing The Sims is making sure that your Sim succeeds in life and achieves a different goal in each life stage. A baby, toddler, or child that is not taken care of by other Sims can be taken away by social workers. A Young Adult can get kicked out of college if he or she gets below passing grades for two semesters in a row. An adult that misses work too much can get fired from their job.


To stop the aging process for all of your Sims in the active family, press "Control" + "Shift" + "C" simultaneously. Type in aging off and press "Enter". To resume aging, type in aging on.
To stop the aging process for individual Sims, press "Control" "Shift" "C" simultaneously. Type in agesimscheat on and click on the specific Sim. The option "Set Age" will appear in their menu, as you can switch their life style or age group to something else. Be sure to type in agesimscheat off after you're done.
Use the "Elixir of Life" aspiration reward for sims who are teen or older. This method keeps them young for an additional 3 days per drink.
Learn the different stages.
Keep a mental note of each aging cycle.
Take care of your Sims through each stage.
Use cheats on the aging process.
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